How to Fix 'This Copy of Windows Is Not Genuine' Errors

Screenshot of the Windows 7 not genuine error message

Windows will show “not genuine” messages if your copy of Windows isn’t properly activated. Product activation is necessary so that Microsoft knows that you obtained Windows legally and to limit the number of computers the same product key is used on.

A number of other things beyond error messages might happen if you don't fix the "Windows is not genuine" problem. If your copy of Windows isn’t activated, your computer might log you out every hour, or reboot occasionally, or give you a permanent black desktop, or even prevent you from installing some Windows updates.

What the Error Looks Like

The error is different depending on the Windows version. For example, when Windows 7 Build 7601 isn’t genuine, you’ll see this error:

Windows 7
Build 7601
This copy of Windows is not genuine

You’ll probably also get occasional pop-ups or see messages in other parts of Windows. Here are some examples:

  • "Windows is not genuine." "Click this message to learn how to get genuine."
  • "Activate Windows" "Go to Settings to activate Windows."
  • "The copy of Windows you are using does not pass genuine validation."
  • "Activate Windows now" "The activation period has expired. Click this message to start activation."
  • "This copy of Windows is not genuine." "You may be a victim of software counterfeiting."
  • "This copy of Microsoft Windows is not genuine." "Your copy of Microsoft Windows must be validated as genuine."
  • "This computer is not running genuine Windows" "To use Windows without interruption, this computer needs to be running genuine Windows."
  • "You must activate today." "Activate Windows now"

Why You’re Seeing This Error

The most likely reason for a error like “This copy of Windows is not genuine” is because it’s legitimately not genuine! This will happen if you’ve installed Windows without a valid product key, but then tricked the operating system into thinking it’s activated through the use of a keygen utility or other hack.

Unfortunately, hacks like that do usually work, and often indefinitely. However, if Windows identifies the hack—which is usually the case if you use Windows Update—you’ll be told so through various messages.

A less common reason for these activation errors is if malware has attacked your computer in such a way that the valid activation files you had before the infection are now corrupted or missing and Windows can’t verify the authenticity of your copy of Windows.

How to Fix ‘Windows Is Not Genuine’

There are several things you can try to fix the “Windows is not genuine” message, but not every method is “official.” Some, which are explained at the bottom of this page, provide a workaround to remove the message and restore regular access to Windows, but they aren’t approved or supported by Microsoft.

Enter a Valid Product Key

Screenshot of the Enter a product key screen in Windows 8

If this is your first time using your computer since you installed Windows, but you haven’t yet entered the product key, the best way to remove the “Windows is not genuine” error is to enter your product key to activate Windows.

You can change your Windows product key through Control Panel in Windows 10, 8, 7, and Vista. Changing the Windows XP product key is done through the registry.

Another way to enter a different product key in Windows is through the Run dialog box. Open it with WIN+R and then enter the following, followed by Enter:

slui.exe 3

to get a prompt where you can type your product key.

Reset the License Information

This fix for “Windows is not genuine” errors resets the information used to activate Windows. If the information is valid but somehow corrupted, this should remove the error.

Screenshot of the 'slmgr -rearm' command in a Windows 7 Command Prompt
  1. Type the following, followed by Enter:

    SLMGR -REARM

    If you see an error message, try this intead:

    SLMGR /REARM
  2. Wait for the command to finish running.

  3. Click OK on the “Command completed successfully.” pop-up message.

  4. Follow any activation instructions if you see them after Windows starts back up.

Disable the Plug and Play Policy

This method only applies to some versions of Windows.

You might be able to fix the “not genuine” error by disabling the Plug and Play Group Policy object. This might be the case if the Network Service account doesn’t have the proper permissions to access the HKU\S-1-5-20 registry key.

Screenshot of the Plug and Play Group Policy object in Windows 7
  1. Open the Run dialog box with the WIN+R keyboard shortcut.

  2. Type the following, followed by Enter:

    rsop.msc
  3. Go to Computer Configuration > Windows Settings > Security Settings > System Services.

  4. Locate Plug and Play from the list.

    If Plug and Play is set to anything other than Not Defined (look in the “Startup” column), then continue with the next step.

    If you see Not Defined in that column, then these steps will not work to fix the “Windows is not genuine” error.

  5. Locate the Group Policy listed next to Plug and Play.

  6. Change the Group Policy setting to Not Defined.

  7. Open the Run dialog box again via the WIN+R keyboard shortcut and then enter the following, followed by Enter:

    gpupdate /force
  8. Restart your computer.

  9. You might need to complete some activation instructions after Windows loads.

Apply the Proper Registry Permissions

If the above steps didn’t work to fix the error about Windows not being genuine, or you couldn’t complete them because of what you found during Step 4, you can try adjusting the permissions Network Service has to access a specific registry key.

Screenshot of registry permissions in Windows 7
  1. Locate HKEY_USERS\S-1-5-20.

    You’d be wise to back up the registry at this time before making any changes. You can back up just the HKEY_USER hive since that’s the only area you’ll be working in.

  2. Right-click S-1-5-20 and click Permissions.

  3. Click Add under “Group or user names” if NETWORK SERVICE isn’t already listed.

    If you do see it, skip down to Step 7.

  4. Type network service in the text box and click Check Names.

  5. Click OK.

  6. Click NETWORK SERVICE.

  7. Put a check in the box next to both Full Control and Read, under the “Allow” column.

  8. Click OK.

  9. Restart your computer.

  10. Complete any activation prompts that pop up after Windows loads.

Delete the KB971033 Update

This method applies to Windows 7 only.

If Windows 7 won’t activate properly, there might be an issue with an update that was installed via Windows Update, specifically, one for Windows Activation Technologies (KB971033).

It's used by Microsoft to detect whether Windows is genuine, and that’s how it knows to limit your computer and show you the “Windows is not genuine” errors.

However, if you know that your product key is genuine and that you aren’t using a pirated copy of Windows, you can remove the update to, hopefully, delete the error about Windows not being genuine.

Screenshot showing how to uninstall KB971033 in Windows 7
  1. Go to Start > Control Panel.

  2. Open Programs and Features.

    If you don't see that option, go to Programs first and then Programs and Features.

  3. Click View installed updates on the left.

  4. Search for KB971033 from the list of installed updates.

  5. Right-click the update and click Uninstall.

  6. Click Yes on the confirmation prompt, and then wait for Windows to uninstall the update.

  7. Restart your computer.

It’d be a good idea to now check for updates again with Windows Update and then install any available ones (like KB971033). It might not make sense to reinstall the same update that caused the error in the first place, but it’s possible that the update installed incorrectly the first time around; trying again will allow the update another chance at installing properly.

However, if you know that your computer is unable to remain functional while that update is installed, remove it and then don't install it again.

Install KMSpico

KMSpico is a Windows hack that tricks the operating system into thinking it’s activating with a real license server, when in reality, the program installs the server on your own computer and then activates the product key against your own machine.

This method for making Windows genuine again is not legal, so we won’t link to the program. However, if you did purchase your product key completely legally but are having issues removing the “Windows is not genuine” error, this is a last resort you might want to consider trying.

Check Your Computer for Malware

A virus is an unlikely reason for a “Windows is not genuine” message, but you can’t rule it out without checking.

There are lots and lots of programs you can use to check for various types of malware, including on-demand scanners, spyware cleaners, and full antivirus software programs.

Another option is a bootable antivirus tool. These are useful if you can’t even boot into Windows to run a scan, because they work before Windows starts. You’ll have to a have a flash drive or disc to use a bootable malware cleaner.

Reinstall Windows

Deleting Windows from your computer and reinstalling it is, of course, the most drastic solution to a "Windows is not genuine" error. However, if you've tried all of the above and Windows still won't properly activate, you're left with starting from scratch.

Before installing Windows over your current version, make sure to have a copy of your Windows product key so that you can avoid having to buy a brand new copy. You can use a key finder tool to locate your Windows product key.