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 legallyandto limit the number of computers the same product key is used on.

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

How to Fix 'Windows Is Not Genuine'

You can try several things to fix the "Windows is not genuine" message, but which one is best to try depends on your situation and what you see, so read through the various tactics below before getting started.

1. Enter a Valid Product Key. 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 stop this error is to enter your product key to activate Windows.

   You can change your Windows product key through Settings in Windows 11, or 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. Openit withWIN+Rand then enter the following:

    slui.exe 3

   You'll get a prompt where you can type the product key.

2. 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.

   1. Open an elevated Command Prompt.
   2. Typethe following, followed byEnter: SLMGR -REARM
      If you seean error message, try this instead: SLMGR -REARM
   3. Wait for the command to finish running.
   4. SelectOKon the "Command completed successfully." pop-up message.
   5. Restart your computer.
   6. Follow any activation instructions if you see them after Windows starts back up.
   7. Put a check in the box next to bothFull Control and Read, under the "Allow" column.

3. 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 theHKU\S-1-5-20registry key.

   1. Open the Run dialog box with theWIN+Rkeyboard shortcut.
   2. Type the following, followed byEnter: rsop.msc
   3. Go toComputer Configuration>Windows Settings>Security Settings>System Services.
   4. LocatePlug and Playfrom the list.
      If Plug and Playis set to anything other thanNot Defined(look in the "Startup" column), then continue with the next step.
      If you see Not Definedin that column (like the image below), then these steps will not work to fix the "Windows is not genuine" error.
   5. Locatethe Group Policy listed next toPlug and Play.
   6. Change the Group Policy setting toNot Defined.
   7. Open the Run dialog box again via theWIN+Rkeyboard shortcut and then enter the following, followed byEnter: gpupdate /force
   8. Restart your computer.
   9. You might need to complete some activation instructions after Windows loads.

4. 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.

   1. Open Registry Editor.
   2. Locate HKEY_USERS\S-1-5-20.
   3. Right-clickS-1-5-20and selectPermissions.
      ChooseAddunder "Group or user names" ifNETWORK SERVICEisn't already listed.
   4. If you do see it, skip down to Step 7.
   5. Type network servicein the text box and selectCheck Names.
   6. SelectOK.
   7. SelectNETWORK SERVICE.
   8. Put a check in the box next to both Full Control and Read, under the "Allow" column.
   9. SelectOK.
   10. Restart your computer.
   11. Complete any activation prompts that pop up after Windows loads.
       

   We recommend backing up the registry at this point,beforemaking any changes. You can back up just the HKEY_USER hive since that's the only area you'll be working in.

5. 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 installed via Windows Update, specifically, one for Windows Activation Technologies (KB971033).

   If you know that your product key is genuine, removing and reinstalling this update could solve this problem.

   1. Go toStart>Control Panel.
   2. Open Programs and Features.
      If you don't see that option, go toProgramsfirst and thenPrograms and Features.
   3. SelectView installed updateson the left.
   4. Search forKB971033from the list of installed updates.
   5. Right-click the update and selectUninstall.
   6. SelectYeson 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 a fresh version of this KB971033 update. It might not make sense to reinstall the same update that caused the error in the first place, but the update could have been installed incorrectly; trying again will allow the update another chance at installing properly.

6. 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.

   You can use plenty of programs 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 need a flash drive or disc to use a bootable malware cleaner.

7. Reinstall Windows. Of course, deleting Windows from your computer and reinstalling it is 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 to avoid having to buy a brand new copy.

   See How to Properly Delete and Reinstall Windows for help.
   

Causes of 'This Copy of Windows Is Not Genuine' Errors

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."

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 7Build 7601This copy of Windows is not genuine

The most likely reason for an 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, and now the operating system, probably after a Windows Update, is letting you know.

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