HP Diagnostics Key: How to Test Your HP Laptop or Desktop

If your HP laptop or desktop is experiencing startup problems, crashes, memory errors, battery issues, or suspected hardware failure, HP PC Hardware Diagnostics can help determine whether a hardware component is causing the problem.

On many HP computers, the HP diagnostics key is F2. You can typically access the diagnostic utility by turning on or restarting the computer, repeatedly pressing Esc to open the HP Startup Menu, and then pressing F2 to launch HP PC Hardware Diagnostics UEFI.

HP’s diagnostic tools can test several important hardware components, including:

• Memory (RAM)
• Hard drive or solid-state drive (SSD)
• Battery
• Processor
• System board
• Keyboard and other input devices
• Additional hardware supported by the particular HP computer

Because HP PC Hardware Diagnostics UEFI runs outside the Windows operating system, it can be especially useful when Windows will not start or when you need to determine whether a problem is being caused by hardware rather than software.

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Quick Answer: What Is the HP Diagnostics Key?

For many HP laptops and desktops, the diagnostic key is F2.

To open HP hardware diagnostics:

1. Turn off the HP computer.
2. Turn the computer back on.
3. Immediately press the Esc key repeatedly until the Startup Menu appears.
4. Press F2 for System Diagnostics.
5. Select the hardware test you want to run.

If HP PC Hardware Diagnostics is installed and available on the computer, the diagnostic environment should open without requiring Windows to start.

If pressing F2 doesn’t open the diagnostic utility, don’t worry. HP provides additional diagnostic options, including downloadable HP PC Hardware Diagnostics tools and USB-based diagnostics, which we’ll cover below.

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How to Open HP PC Hardware Diagnostics UEFI with F2

HP PC Hardware Diagnostics UEFI allows you to test hardware independently of Windows. This is particularly useful when an HP computer will not boot normally or when you are trying to determine whether a problem is related to hardware or the operating system.

On many HP laptops and desktops, you can access the diagnostic environment from the HP Startup Menu.

Step 1: Shut Down the HP Computer

Save any open work and completely shut down the computer.

If Windows will not start, power off the computer before beginning the diagnostic process.

Step 2: Turn On the Computer and Press Esc

Turn the HP computer back on and immediately begin pressing the Esc key repeatedly.

Continue until the HP Startup Menu appears.

You may need to begin pressing Esc as soon as the computer powers on. If Windows begins loading, restart the computer and try again.

Step 3: Press F2 for System Diagnostics

From the HP Startup Menu, press:

F2 – System Diagnostics

This should launch HP PC Hardware Diagnostics UEFI when the diagnostic environment is available on the computer.

On some HP systems, repeatedly pressing F2 immediately after powering on may also open the diagnostic utility.

Step 4: Select the Hardware Test

Once HP PC Hardware Diagnostics opens, the available tests depend on the computer and version of the diagnostic utility.

You may see options for testing components such as:

• Processor
• Memory
• Hard drive or SSD
• Battery
• System board
• Keyboard
• Audio
• Network hardware
• Other supported components

You may also have options for a Fast Test, Quick Test, Extensive Test, or individual component tests.

Step 5: Record Any Failure ID or Error Information

If a hardware component fails a diagnostic test, write down or photograph the information displayed on the screen.

HP diagnostics may generate a 24-digit Failure ID along with information identifying the affected component.

Keep this information available if you need to contact HP Support, arrange warranty service, or provide the diagnostic results to an IT technician.

A failed hardware diagnostic is considerably more useful for troubleshooting than a general symptom such as “the computer is slow” or “Windows keeps crashing” because it can help identify the specific component experiencing a problem.

What If F2 Does Not Open HP Diagnostics?

If pressing F2 doesn’t launch HP PC Hardware Diagnostics, don’t assume there is no way to test the computer.

Try the following:

1. Shut down the computer completely.
2. Turn it back on.
3. Immediately press Esc repeatedly.
4. Wait for the HP Startup Menu.
5. Select F2 – System Diagnostics.

If the diagnostic option is missing, doesn’t load, or the diagnostic files are unavailable, you may need to use HP’s downloadable diagnostic software or create an HP PC Hardware Diagnostics UEFI USB drive.

We’ll cover that process below.

HP Startup Keys: Esc, F2 and F10

It is easy to confuse the different HP startup keys because they perform different functions.

For many HP computers:

• Esc – Opens the HP Startup Menu
• F2 – Opens System Diagnostics
• F10 – Opens BIOS Setup

If your objective is to test the computer’s hardware, F2 is the key you’re primarily looking for.

If pressing F2 directly doesn’t work, use Esc first and then select F2 from the Startup Menu.

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Which HP Hardware Tests Should You Run?

Once you open HP PC Hardware Diagnostics, you may have several different tests available. The exact options vary by HP model and diagnostic version, but the goal is to test the component most closely related to the problem you’re experiencing.

If you’re unsure where to begin, start with the shorter system tests and then run more extensive component tests if the problem remains unresolved.

HP Memory Test

Run the Memory Test if the computer is experiencing symptoms such as:

• Random crashes or restarts
• Blue screen errors
• Freezing
• Applications unexpectedly closing
• Problems starting Windows
• Suspected RAM failure

A memory test checks the computer’s RAM for hardware-related errors.

If the memory test fails, record the Failure ID and other information displayed by HP Diagnostics. A failed memory test can indicate a problem with a memory module or another part of the memory subsystem.

HP Hard Drive or SSD Test

Run the storage test when you’re experiencing:

• Windows failing to start
• Extremely slow file access
• Disk-related errors
• Files becoming corrupted
• Frequent freezing
• Clicking or unusual noises from a mechanical hard drive
• Suspected hard drive or SSD failure

Depending on the system, HP Diagnostics may provide multiple storage tests, including shorter checks and more extensive tests.

If a quick storage test passes but you still suspect a drive problem, run the more comprehensive test when available.

A failed storage diagnostic should be taken seriously, particularly if important data is stored on the computer.

If you suspect a drive is failing and the computer is still accessible, prioritize backing up important data before continuing to use the system extensively.

HP Battery Test

For HP laptops, run the Battery Test if you notice:

• Short battery life
• Battery not charging
• Unexpected shutdowns while on battery power
• Battery percentage changing unexpectedly
• A battery replacement warning
• The laptop only working reliably when connected to AC power

HP’s battery diagnostics can help determine the condition of the battery and whether replacement may be necessary.

Battery performance naturally declines over time, so reduced runtime alone does not necessarily indicate another problem with the laptop.

HP Processor Test

The processor diagnostic checks aspects of CPU functionality.

A processor test may be useful when investigating unexplained system instability, startup problems, or other symptoms where a hardware issue is suspected.

Processor failures are generally less common than problems involving storage, batteries, or memory, so use the symptoms and other diagnostic results to guide your troubleshooting.

HP System Board Test

Some versions of HP PC Hardware Diagnostics provide tests for the system board or related components.

The system board connects many of the computer’s major hardware components, so a failure involving the motherboard can produce a wide range of symptoms.

If HP Diagnostics reports a system board failure, record the Failure ID and other diagnostic information before arranging service.

Keyboard and Input Device Tests

HP Diagnostics may also include interactive tests for components such as the keyboard, mouse, touchpad, touchscreen, or other input devices.

These tests can be useful when:

• Certain keyboard keys don’t respond
• The touchpad behaves unexpectedly
• An input device works intermittently
• You need to distinguish between a hardware problem and a Windows or driver problem

Quick Test vs. Extensive Test

HP diagnostic versions may provide different levels of testing.

A Quick Test or similar short test is a good place to begin because it can identify obvious hardware problems relatively quickly.

If the shorter test passes but the computer continues experiencing symptoms, consider running an Extensive Test or individual component tests.

More comprehensive tests can take considerably longer, especially when testing storage or memory.

What Does It Mean If All HP Diagnostics Pass?

Passing HP hardware diagnostics is useful information, but it does not necessarily mean there is nothing wrong with the computer.

If the hardware tests pass, the problem could still involve:

• Windows
• Device drivers
• Software
• Malware
• Corrupted system files
• Updates
• Application conflicts
• Network connectivity
• Intermittent hardware problems not detected during the test

Diagnostics are one part of the troubleshooting process.

A failed test provides strong evidence that a hardware component needs attention. A passed test helps narrow the investigation, but troubleshooting may need to continue if the original problem remains.

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How to Create an HP PC Hardware Diagnostics UEFI USB Drive

If HP PC Hardware Diagnostics UEFI is not available on the computer’s internal storage, HP provides a downloadable version that can be installed on a USB flash drive.

A diagnostic USB drive can be especially useful when:

• Windows will not start
• The built-in HP diagnostics environment is missing
• F2 does not successfully launch diagnostics
• The computer’s storage drive may be failing
• You need to test multiple HP computers
• You want access to a newer version of HP’s diagnostic tools

Because the diagnostic environment runs independently of Windows on the computer being tested, you may still be able to diagnose hardware even when the operating system cannot boot.

What You Need

Before creating the diagnostic USB drive, have the following available:

• A working Windows computer
• A USB flash drive
• Internet access
• The current HP PC Hardware Diagnostics UEFI installer from HP

If the HP computer you’re troubleshooting is unusable, you can create the USB diagnostic drive on another working computer.

Download HP PC Hardware Diagnostics UEFI

Download HP PC Hardware Diagnostics UEFI from HP’s official support website.

HP offers diagnostic utilities for testing HP computers, and the available download or installation options can change as HP updates the software.

Whenever possible, obtain the utility directly from HP rather than downloading diagnostic software from an unofficial third-party website.

Create the HP Diagnostics USB Drive

After downloading the HP PC Hardware Diagnostics UEFI package:

1. Insert the USB flash drive into the working computer.
2. Run the HP diagnostic installer.
3. Follow the installation prompts.
4. Select the option to install the diagnostic utility to a USB flash drive when offered.
5. Select the appropriate USB drive.
6. Allow the installation process to complete.
7. Safely remove the USB drive.

Be careful to select the correct drive during installation.

The exact screens and wording may vary depending on the version of HP PC Hardware Diagnostics you download.

How to Run HP Diagnostics From USB

Once the diagnostic USB drive has been created:

1. Shut down the HP computer you want to test.
2. Insert the HP diagnostics USB drive.
3. Turn on the computer.
4. Immediately press the Esc key repeatedly to open the HP Startup Menu.
5. Press F2 to access System Diagnostics.
6. Allow HP PC Hardware Diagnostics UEFI to load.
7. Select the appropriate hardware test.

If the diagnostic environment does not load automatically, the computer’s boot configuration or the particular HP model may require additional troubleshooting.

Why a USB Diagnostic Drive Is Useful

A USB diagnostic environment can help separate a hardware problem from a Windows problem.

For example, suppose an HP computer repeatedly crashes in Windows. If you boot into HP PC Hardware Diagnostics UEFI from USB and the memory test fails, you now have strong evidence of a hardware problem independent of Windows.

On the other hand, if extensive hardware diagnostics pass, you may need to investigate Windows, drivers, applications, malware, updates, or other software-related causes.

What Is the HP PC Hardware Diagnostics 3-in-1 USB Key?

You may encounter references online to an HP PC Hardware Diagnostics 3-in-1 USB Key.

This terminology has been associated with HP diagnostic and service tools used to create bootable USB media for troubleshooting HP computers.

Older versions and service-oriented diagnostic tools may look different from HP’s current consumer diagnostic environment. This is important because older instructions found online may reference prompts, menus, or technician information that do not appear in current versions of HP PC Hardware Diagnostics.

If you’re troubleshooting a modern HP computer, start with the current HP diagnostic tools provided by HP rather than assuming older screenshots or procedures will exactly match your system.

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What Is the HP Diagnostics CSO Number and Agent ID?

If you’re using an older version of the HP PC Hardware Diagnostics 3-in-1 USB Key or another service-oriented HP diagnostic utility, you may encounter prompts asking for a CSO Number and Agent ID before the diagnostic tests become available.

We originally encountered this issue while using HP’s diagnostic utility in 2016.

What Is an HP CSO Number?

In the HP diagnostic utility we used, CSO stood for Customer Service Order.

The field appeared to be intended for HP service personnel or field technicians to associate the diagnostic session with a particular service call.

The problem for someone independently diagnosing an HP computer was straightforward: the utility asked for a CSO Number even though we did not have an HP service order.

What Worked for Us

When the diagnostic utility requested a CSO Number, we entered:

1234

The utility accepted it.

It then requested an Agent ID, where we again entered:

1234

After entering those values, we were able to proceed to the diagnostic testing options.

Readers Confirmed the Workaround

One of the useful aspects of the original version of this article is that several readers subsequently reported their own experiences with the workaround.

In comments posted during 2016, multiple readers reported that the technique worked for them, including users who said it continued to work with later versions of the HP diagnostic utility available at the time.

One reader discovered an additional limitation: after using the same CSO value on another HP laptop with the same diagnostic USB key, the utility reported an identical CSO error. The reader reported that changing the number to 2345 allowed the diagnostic process to continue.

These reports apply to the older HP diagnostic utilities being discussed at the time and should not be interpreted as instructions for current versions of HP PC Hardware Diagnostics.

Do Current HP Diagnostics Require a CSO Number?

Current HP diagnostic tools may look considerably different from the versions discussed in this article’s original 2016 instructions and reader comments.

You may not encounter a CSO Number or Agent ID prompt at all when using a current version of HP PC Hardware Diagnostics UEFI.

For that reason, 1234 should not be considered an official or universal HP CSO Number or Agent ID. It is a workaround that worked with the older diagnostic environment we used and that multiple readers reported successfully using at the time.

If you’re troubleshooting a newer HP computer, start with the current HP PC Hardware Diagnostics procedure. The legacy CSO information remains here for people working with older HP diagnostic tools that still present these prompts.

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What Is an HP Failure ID?

When HP PC Hardware Diagnostics detects a hardware problem, it may display a 24-digit Failure ID, sometimes referred to as a failure code.

The Failure ID provides information about the diagnostic test and the hardware problem that was detected. It can be useful when contacting HP Support, checking warranty options, or providing diagnostic information to an IT technician.

If you receive an HP Failure ID, write it down or take a clear photo of the diagnostic screen before exiting the utility.

What Should You Record When an HP Diagnostic Test Fails?

Record as much information as the diagnostic utility provides, including:

• 24-digit Failure ID
• Product ID
• Component that failed
• Test that was performed
• Failure message or error code
• HP computer model
• Serial number, if needed for support

Taking a photo of the entire results screen with your phone is often the easiest way to make sure you don’t lose important diagnostic information.

What Does a Failed HP Hardware Test Mean?

A failed HP diagnostic test generally indicates that the utility detected a problem with the hardware component being tested.

For example:

Memory test failure: The computer may have a problem involving RAM or the memory subsystem.

Storage test failure: The hard drive or SSD may be experiencing a hardware problem.

Battery test failure: The laptop battery may have deteriorated or require replacement.

System board test failure: The computer may require more extensive hardware service.

The appropriate next step depends on the component, computer model, warranty status, and exact diagnostic result.

What Should You Do If the Hard Drive or SSD Fails?

A failed storage diagnostic deserves immediate attention.

If the computer still starts and important data has not already been backed up, prioritize protecting your data. A failing storage device can potentially become less reliable or stop functioning entirely.

Avoid unnecessary use of a drive that appears to be failing.

After protecting important data where possible, the storage device may need to be replaced and the operating system restored or reinstalled.

For a business computer, contact your IT provider so the failure can be handled in a way that protects company data and minimizes downtime.

What Should You Do If the Memory Test Fails?

If HP Diagnostics reports a memory failure, the computer’s RAM or related hardware may require service.

Depending on the HP model, memory may be replaceable, partially integrated into the system board, or completely soldered to the motherboard.

Record the Failure ID and computer model before attempting repairs or ordering replacement components.

Does a Failure ID Mean the Computer Is Under Warranty?

No.

An HP Failure ID indicates the result of a diagnostic test; it does not determine whether the computer is currently covered by warranty.

Check the computer’s warranty status separately using its serial number or Service Tag information requested by HP.

If the computer is covered, HP may use the Failure ID and other diagnostic information when determining the appropriate repair procedure.

What If HP Diagnostics Says Everything Passed?

If all HP hardware diagnostics pass but the original problem continues, further troubleshooting may be necessary.

The issue could involve:

• Windows
• Drivers
• Software conflicts
• Corrupted system files
• Malware
• Updates
• Network problems
• Intermittent hardware issues
• Hardware not covered by the particular test

A Passed result means the diagnostic test did not identify a failure during that test. It should not be interpreted as a guarantee that every component of the computer is functioning perfectly.

Keep the Failure ID for Support or Repair

If a test fails, don’t repeatedly run the same diagnostic without first recording the result.

The Failure ID can provide valuable information when you contact HP or an IT professional and may save time by showing that a specific hardware diagnostic has already failed.

In a business environment, documenting the Failure ID in the support ticket also creates a useful record of what was tested, what failed, and why hardware repair or replacement was recommended.

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HP Diagnostics vs. Windows Diagnostics: Which Should You Use?

HP PC Hardware Diagnostics and troubleshooting tools within Windows can both help diagnose computer problems, but they serve different purposes.

The biggest advantage of HP PC Hardware Diagnostics UEFI is that it can run independently of Windows. This allows you to test important hardware components even when Windows will not start correctly.

When to Use HP PC Hardware Diagnostics UEFI

HP’s UEFI diagnostics are particularly useful when you suspect a physical hardware problem.

Consider running HP hardware diagnostics when:

• The computer will not boot into Windows
• The computer randomly freezes or restarts
• You receive storage-related errors
• You suspect the hard drive or SSD is failing
• You suspect faulty memory
• An HP laptop has battery or charging problems
• The computer experiences unexplained hardware-related errors
• You need a diagnostic result before contacting HP Support
• You want to determine whether a problem occurs independently of Windows

Because these tests operate outside the normal Windows environment, they can help separate a hardware failure from an operating-system or software problem.

When to Troubleshoot Within Windows

If HP hardware diagnostics pass, Windows-based troubleshooting may be the logical next step.

Problems that may require further investigation within Windows include:

• Device driver problems
• Corrupted Windows system files
• Failed or incomplete Windows updates
• Software conflicts
• Startup application problems
• Malware
• Network configuration issues
• Application errors
• Performance problems
• Printer or peripheral configuration issues

Passing HP hardware diagnostics can therefore help narrow the troubleshooting process.

Example: Computer Is Freezing

Suppose an HP laptop repeatedly freezes.

There could be many possible causes, including failing memory, a storage problem, Windows corruption, a problematic driver, overheating, malware, or a software conflict.

Running HP PC Hardware Diagnostics gives you a useful starting point.

If the Memory Test fails, you have evidence pointing toward a hardware problem.

If the Storage Test fails, the SSD or hard drive requires attention.

If the major hardware tests pass, you can continue investigating Windows, drivers, applications, and other possible causes.

Example: Windows Will Not Boot

HP PC Hardware Diagnostics can be especially valuable when Windows will not start.

Since the UEFI diagnostic environment does not depend on Windows loading normally, you may still be able to test the computer’s memory and storage.

If the SSD fails its diagnostic test, for example, that may help explain why Windows cannot boot.

If the storage and memory tests pass, the next troubleshooting steps may involve Windows startup repair, system recovery, operating-system corruption, or other software-related issues.

HP Diagnostics and Windows Troubleshooting Work Together

You generally do not need to choose one diagnostic approach exclusively.

Think of the process as narrowing down the problem:

First determine whether there is evidence of a hardware failure.

If HP PC Hardware Diagnostics identifies a failed component, address that hardware problem.

If the hardware tests pass, continue troubleshooting the operating system, drivers, applications, and other software-related causes.

This approach can prevent wasting time repeatedly repairing Windows when the underlying problem is actually a failing SSD, bad memory, or another hardware component.

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HP Diagnostics: Common Problems and Troubleshooting

HP PC Hardware Diagnostics is generally straightforward to use, but the diagnostic environment may not always open or behave as expected. The exact options available can also vary depending on the HP model and version of the diagnostic software.

Here are some common problems to check.

F2 Does Not Open HP Diagnostics

If pressing F2 does not launch HP PC Hardware Diagnostics:

1. Shut down the computer completely.
2. Turn it back on.
3. Immediately begin pressing the Esc key repeatedly.
4. Wait for the HP Startup Menu to appear.
5. Press F2 for System Diagnostics.

Timing matters. If Windows begins loading, restart the computer and try again.

If the Startup Menu appears but F2 diagnostics are unavailable or will not load, the diagnostic environment may not be installed or accessible on the computer.

In that situation, consider creating an HP PC Hardware Diagnostics UEFI USB drive using HP’s current diagnostic software.

HP Diagnostics Will Not Load

If the diagnostic option appears but the utility will not load, try completely shutting down the computer and attempting the process again.

If the problem continues, using the USB version of HP PC Hardware Diagnostics can help determine whether the locally installed diagnostic environment is the problem.

A failure to load HP Diagnostics does not by itself mean the computer has a hardware failure.

HP Diagnostics USB Drive Is Not Recognized

If you created an HP diagnostics USB drive but the computer does not recognize it:

• Verify that the USB drive was created successfully.
• Try another USB port.
• Recreate the diagnostic USB using the current HP utility.
• Make sure you selected the correct USB drive during creation.
• Shut down the HP computer completely before trying again.
• Insert the USB drive before powering on the computer.
• Open the Startup Menu with Esc and then try F2 again.

Boot and security settings can vary among HP models, so additional troubleshooting may be necessary if the USB diagnostic environment still does not load.

HP Hardware Test Freezes or Never Finishes

Some extensive hardware tests can take considerably longer than quick tests, particularly storage and memory diagnostics.

Allow the test sufficient time to complete.

However, if the diagnostic utility repeatedly freezes, becomes unresponsive, or stops at the same point, document what happened and which component was being tested.

Repeated diagnostic failures or freezes can themselves provide useful information when troubleshooting the computer, although they do not automatically identify the failed component.

HP Diagnostics Says Passed but the Computer Still Has Problems

A Passed result means the diagnostic test did not detect a failure during that particular test.

It does not guarantee that the computer has no hardware or software problems.

If the original issue continues after HP diagnostics pass, investigate other possibilities such as:

• Windows corruption
• Device drivers
• Software conflicts
• Failed updates
• Malware
• Startup applications
• Network problems
• Overheating
• Intermittent hardware problems
• Hardware that was not covered by the test

For intermittent problems, you may also want to run the more extensive version of the applicable hardware test.

HP Diagnostics Reports a Failure ID

If a diagnostic test fails and displays a Failure ID, stop and record the information before exiting the utility.

Take a photo of the results screen or write down:

• Failure ID
• Product ID
• Failed component
• Test name
• Error or failure message

You can use this information when contacting HP Support or an IT professional.

If the failed component is the hard drive or SSD and the computer still provides access to important files, protecting the data should become a priority.

The HP Diagnostics Screen Looks Different From Online Instructions

This is normal.

HP diagnostic utilities have changed over time, and different HP computers may contain different versions of the software.

Older diagnostic environments may include screens or prompts that are not present in current HP PC Hardware Diagnostics UEFI.

For example, older service-oriented versions may ask for a CSO Number or Agent ID, while current diagnostic workflows may instead focus on component testing and Failure IDs.

Follow the options available on your particular computer rather than assuming every HP diagnostic screen will look identical.

When HP Diagnostics Is Not Enough

HP PC Hardware Diagnostics is primarily designed to help identify hardware problems.

If the hardware tests pass but the computer continues experiencing problems, further troubleshooting may be necessary.

That could involve checking:

• Windows event logs
• Device Manager
• Storage health
• Drivers
• Windows system files
• Software and startup applications
• Malware and endpoint security
• Network connectivity
• Operating temperatures
• Other manufacturer-specific diagnostics

For a business computer, persistent problems should generally be documented and escalated to your IT provider rather than repeatedly running the same diagnostic tests without addressing the underlying issue.

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HP Diagnostics Key: Key Takeaways

HP PC Hardware Diagnostics provides a useful way to test an HP laptop or desktop for hardware problems, especially when you need to determine whether an issue is being caused by a physical component or by Windows and software.

Here are the most important points to remember:

• F2 is the primary HP diagnostics key on many HP computers.
• If pressing F2 directly does not work, restart the computer, repeatedly press Esc to open the HP Startup Menu, and then select F2 – System Diagnostics.
• F10 is typically used for BIOS Setup, not hardware diagnostics.
• HP PC Hardware Diagnostics UEFI runs independently of Windows, making it useful when Windows will not start normally.
• HP Diagnostics can test components such as memory, storage, battery, processor, system board, keyboard, and other supported hardware.
• Start with a Quick Test when available, then run more extensive or component-specific tests if the problem continues.
• If a test fails, record or photograph the Failure ID and diagnostic results before exiting.
• A failed hard drive or SSD test should be taken seriously. Protect important data as soon as practical if the drive is still accessible.
• If the built-in diagnostics are unavailable, you can create an HP PC Hardware Diagnostics UEFI USB drive on another computer.
• Older HP diagnostic utilities may ask for a CSO Number and Agent ID. These prompts are associated with older service-oriented diagnostic environments and may not appear in current versions.
• The 1234 CSO Number and Agent ID values described in this article worked with the older diagnostic utility we encountered, but they should not be considered universal HP credentials.
• Current HP diagnostics may generate a 24-digit Failure ID when a hardware problem is detected.
• A Passed diagnostic does not guarantee that nothing is wrong with the computer. Windows, drivers, software, malware, overheating, intermittent hardware problems, or other issues may still require troubleshooting.
• If HP Diagnostics repeatedly identifies a hardware failure, use the diagnostic results when contacting HP Support or your IT provider.

The basic HP diagnostic process is straightforward:

Turn on the HP computer → press Esc repeatedly → press F2 for System Diagnostics → select a hardware test → record any failure information.

For many hardware problems, this is one of the fastest ways to determine whether troubleshooting should continue within Windows or shift toward repairing or replacing a physical component.

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HP PC Hardware Diagnostics – Frequently Asked Questions

What is the diagnostic key for an HP laptop or desktop?

On many HP laptops and desktops, F2 is the diagnostic key. Turn on or restart the computer and press F2 repeatedly to access HP PC Hardware Diagnostics. If that does not work, repeatedly press Esc during startup to open the HP Startup Menu, then press F2 for System Diagnostics.

What is the F key for HP hardware diagnostics?

The function key for HP hardware diagnostics is typically F2. On many HP computers, you can press Esc repeatedly immediately after turning on the computer and then select F2 from the Startup Menu to launch HP PC Hardware Diagnostics UEFI.

How do I run diagnostics on my HP laptop?

Shut down the HP laptop, turn it back on, and immediately press Esc repeatedly until the Startup Menu appears. Press F2 for System Diagnostics. From HP PC Hardware Diagnostics, select the appropriate test for memory, storage, battery, processor, or another supported component.

What is HP PC Hardware Diagnostics UEFI?

HP PC Hardware Diagnostics UEFI is a diagnostic environment designed to test hardware components in an HP computer independently of Windows. Because it operates outside the normal Windows environment, it can be particularly useful when Windows will not start or when you need to determine whether a problem is hardware-related.

How do I run HP diagnostics if Windows will not start?

You can use HP PC Hardware Diagnostics UEFI, which does not require Windows to start normally. Turn on the computer, repeatedly press Esc to open the Startup Menu, and then press F2 for System Diagnostics. If the built-in diagnostic environment is unavailable, you may be able to create an HP diagnostics USB drive on another working computer.

What hardware can HP Diagnostics test?

Available tests vary by computer and diagnostic version, but HP PC Hardware Diagnostics may provide tests for memory, hard drives and SSDs, batteries, processors, system boards, keyboards, and other supported hardware components.

How do I test the memory on an HP laptop?

Open HP PC Hardware Diagnostics by pressing Esc during startup and then F2 for System Diagnostics. Select the available memory test. If the initial test passes but you still suspect a RAM problem, run a more extensive memory test when available.

How do I test an HP hard drive or SSD?

Open HP PC Hardware Diagnostics UEFI and select the available storage or drive test. Depending on the diagnostic version, shorter and more extensive storage tests may be available. If the hard drive or SSD fails a diagnostic test, record the Failure ID and protect important data as soon as practical if the drive remains accessible.

How do I check my HP laptop battery health?

HP PC Hardware Diagnostics may include a battery test on supported laptops. Open the diagnostic utility and select the battery or power-related test. The results can help determine whether the battery is functioning normally, has deteriorated, or may need replacement.

What does it mean if HP Diagnostics says Passed?

A Passed result means the particular diagnostic test did not detect a hardware failure during that test. It does not guarantee that the computer has no problems. Windows, drivers, software, malware, overheating, intermittent hardware problems, or components not covered by the test may still require investigation.

What is an HP Failure ID?

When HP PC Hardware Diagnostics detects certain hardware failures, it may display a 24-digit Failure ID along with information about the affected component. Record or photograph this information before exiting diagnostics because it can be useful when contacting HP Support or an IT professional.

What should I do if HP Diagnostics detects a hardware failure?

Record the Failure ID, Product ID, failed component, and any other information displayed. If the computer is under warranty, contact HP for available service options. For business computers, provide the results to your IT provider. If a hard drive or SSD fails and remains accessible, protecting important data should become a priority.

Why won’t F2 open HP Diagnostics?

The timing of the key press may be the problem, or the diagnostic environment may not be available on the computer. Shut the computer down, turn it back on, and immediately press Esc repeatedly. When the HP Startup Menu appears, select F2 for System Diagnostics. If diagnostics still will not load, consider using HP PC Hardware Diagnostics from a USB drive.

What is the HP BIOS key?

On many HP computers, F10 opens BIOS Setup. You can typically press Esc repeatedly during startup to display the HP Startup Menu and then select F10 for BIOS Setup. For hardware diagnostics, use F2 rather than F10.

What is the difference between F2 and F10 on an HP computer?

F2 is typically used to access HP System Diagnostics, while F10 is typically used to enter BIOS Setup. If you want to test the computer’s memory, storage, battery, or other hardware, F2 is generally the appropriate option.

Can I run HP Diagnostics from a USB drive?

Yes. HP provides HP PC Hardware Diagnostics UEFI that can be installed on a USB flash drive. This can be useful when the built-in diagnostic environment is unavailable or when Windows will not boot. Create the diagnostic USB on a working computer, connect it to the HP computer being tested, and use the HP startup options to access diagnostics.

What is the HP PC Hardware Diagnostics 3-in-1 USB Key?

The HP PC Hardware Diagnostics 3-in-1 USB Key terminology has been associated with HP diagnostic and service tools used for troubleshooting HP computers from USB media. Older versions may differ significantly from current HP PC Hardware Diagnostics UEFI, so current HP tools and instructions should generally be used for newer computers.

What is a CSO Number in HP Diagnostics?

In the older HP diagnostic utility we encountered, CSO stood for Customer Service Order. The field appeared to be intended for service personnel to associate the diagnostic session with a service call. Current HP PC Hardware Diagnostics versions may not display this prompt.

What should I enter for the HP Diagnostics CSO Number and Agent ID?

When we originally encountered an older HP diagnostic utility that requested a CSO Number and Agent ID, entering 1234 for each field allowed us to continue. This was our experience with that particular older version and should not be considered an official or universal HP CSO Number or Agent ID.

Why does my HP Diagnostics screen look different?

HP has released different diagnostic utilities and versions over time, and the available interface can also vary by computer model. Older service-oriented versions may contain prompts such as CSO Number and Agent ID, while newer HP PC Hardware Diagnostics versions may use a different interface and provide Failure IDs when hardware problems are detected.

Is HP PC Hardware Diagnostics the same as Windows diagnostics?

No. HP PC Hardware Diagnostics UEFI is specifically designed to test supported HP hardware and can operate independently of Windows. Windows troubleshooting tools are useful for operating-system, driver, software, and configuration problems. The two approaches can be used together to help determine whether a problem is hardware- or software-related.

What should I do if all HP hardware tests pass but the computer still has problems?

Continue troubleshooting beyond the hardware diagnostics. Possible causes include Windows corruption, device drivers, software conflicts, malware, failed updates, overheating, network problems, or intermittent hardware issues that were not detected during testing. Running more extensive hardware tests may also be appropriate when symptoms continue.

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Still Having Problems With Your HP Computer?

HP PC Hardware Diagnostics can help identify failing memory, storage, batteries, and other hardware problems, but a diagnostic test is only one part of troubleshooting a computer.

If the hardware tests pass and your HP laptop or desktop continues to experience crashes, startup problems, slow performance, network issues, or other errors, the underlying cause may involve Windows, drivers, software, security, or another part of the system.

Landon Technologies provides professional IT support for small and medium-sized businesses using HP, Dell, Lenovo, and other business computer systems.

Our IT support services can include:

• Remote computer troubleshooting
• Hardware and software diagnostics
• Windows troubleshooting and repair
• Computer performance troubleshooting
• Hardware failure identification
• Warranty and repair coordination
• Driver and software troubleshooting
• Malware and endpoint security investigation
• Business computer monitoring and management
• Backup and data protection
• Remote and on-site IT support

When a Hardware Test Fails

If HP PC Hardware Diagnostics reports a hardware failure, save the Failure ID and diagnostic results before contacting HP or your IT provider.

For business computers, we can help determine the appropriate next step, whether that means coordinating warranty service, replacing a failed component, migrating a user to another computer, restoring data, or replacing the system.

When All HP Diagnostics Pass

A computer can continue having problems even when HP’s hardware diagnostics report that the tested components passed.

In that situation, troubleshooting may need to move into Windows to investigate drivers, software, updates, system files, malware, startup applications, or other potential causes.

The goal is to determine whether the problem is hardware, software, or a combination of both rather than replacing components unnecessarily.

Learn More About Our IT Support Services

Talk With an IT Expert

Related IT Services

Businesses experiencing recurring computer or technology problems may also find these Landon Technologies services helpful:

• Small Business IT Support – Ongoing technical support for business computers, users, software, and technology.
• Remote IT Support – Remote troubleshooting and technical assistance for business computers and users.
• Managed IT Services – Proactive monitoring, maintenance, security, patching, and ongoing management of business technology.
• Cybersecurity Services – Layered protection for business computers, users, networks, email, and data.
• Backup & Disaster Recovery – Business data protection and recovery solutions for hardware failures, cyber incidents, and other disruptions.

More Small Business Technology Tips

Looking for more practical troubleshooting, cybersecurity, Microsoft 365, cloud, and business technology advice?

Visit the Landon Technologies Small Business Tech Tips section for additional guides and resources.

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