Windows Vista Validation Update (KB929391) has just been released and deployed to Vista computer that are what called by Microsoft as “frankenbuild” system that use the workaround of mixing files from RC and RTM build to activate the Windows Vista. As there is no official retail or OEM version of Windows Vista on sale in market yet, so practically all Vista installation by personal or home users is likely to be activated with pirate or crack methods. Your Vista will be de-activated after this update and with Aero feature disabled.

Unactivated Windows Vista will go into reduced functionality mode once the activation grace period expired, where Vista will provide only limited usablity. So if you want to continue using Windows Vista at least until theoretical expiry date of RC1 or RC2 product key in mid 2007, there a few methods that you can try, and should works on all editions of Vista (ultimate, business, enterprise, home premium and etc).

  1. Do not install KB929391 Windows Vista Validation Update. You can turn off Automatic Updates, or at least set it not to automatically install critical updates for you. But if you need to read this article, most likely you have installed it (or Microsoft has pushed it to you), so useless.
  2. Reinstall Windows Vista. Straight forward method, format your hard drive and install fresh Windows Vista again, activate it with various crack or workaround, and then remember the point 1 above.
  3. If you have made a ghost image of your hard drive which Vista is installed, roll back to the previous state of Vista by restoring the image. Also remember point 1 above.
  4. If you have made a CompletePC Backup, boot from Windows Vista DVD, and recover your system by restoring the backup. Remember point 1 above too.
  5. ronie reported the following steps will work to remove the KB929391 update:
    1. Boot from your Vista installation DVD.
    2. Select “Repair your computer”.
    3. Choose “System Restore” and pick a restore point that has been created before the validation update (KB929391) was installed.
    4. As usual, remember point 1 above.
  6. Try to disable, uninstall or remove Windows Vista Validation Update (KB929391) in the hope to undone the ‘damage’ by using following steps. You will need the RC1 or RC2 files of tokens.dat and CPP product key (both is the same as what you used to crack Vista activation previously to make Vista validated and genuine. If you lost the files, download it here) plus Windows Vista DVD. You should backup your important files before trying this.
    1. Reboot Windows Vista, and boot into Safe Mode.
    2. Launch Windows Explorer, go to Folder Options and check (tick or select) “Show Hidden Files” and “Show protected system files” options. Then click OK.
    3. Zap the WPA encrypted store by deleting the following files (hidden by default unless you show hidden file as instructed above):


    4. Uninstall the WGA (Windows Vista Genuine Advantage) update by execute or run the following command:

      regsvr32 /u c:\windows\system32\LegitCheckControl.dll

    5. Reset the Vista Software Licensing tokens file by copying back the RC1 or RC2 tokens.dat to


      Replace the original tokens.dat.

    6. The following step is to remove the Windows Product Activation (WPA) data from the registry. It’s impossible to do this at normal Vista installation bootup, so restart the computer and boot with Windows Vista DVD. Choose to “Repair my Computer” and then select your appropriate Vista installation.
    7. Then select “Command Prompt”, and at command prompt window, type “regedit” (without quotes to run registry editor.
    8. Select HKEY_LOCAL_MACHINE registry branch, and then click on File -> Load Hive.
    9. Navigate to C:\Windows\System32\config and choose the SYSTEM hive. Give it key name of “temp”.
    10. Locate HKEY_LOCAL_MACHINE\temp\WPA\ registry branch and then delete and remove every registry subkeys or child nodes under it. Leave only WPA that is blank. If you already deleted the WPA key, re-create it by right click on HKEY_LOCAL_MACHINE\temp\, and choose New -> Key.
    11. Select HKEY_LOCAL_MACHINE\temp\ and then click on File -> Unload Hive.
    12. Exit from registry editor, exit from command prompt, and then restart the computer.
    13. After booting up normally into Windows Vista, the Vista will be in RFM mode (reduced functionality mode) with message of “Your copy of windows is not genuine.”
    14. Run slui.exe.
    15. Enter any CPP product key (serial key issued during Release Candidate 1 or RC2).
    16. Windows Vista should be activated as genuine.
    17. Log off (logout) and log on (login) again to reactivate Windows Aero interface.
    18. You can now run windows update, by remember point 1 above, uncheck the KB929391 WGA update and if you don’t want to see it forever, hide it.
  7. Simplified and shorter method to recover from the KB929391 Vista Validation Tool that based on the above steps, as found out by joysa. Just execute step 1 – 7 and follow by step 12 – 18, and you’re will be rescued from Vista RFM hell.
  8. Another way to get rid of KB929391 Windows Vista Validation Tool, very similar to step above but requires a new CPP product key:
    1. Create a new Windows Live account.
    2. Obtain a new Windows Vista Release Candidate (RC1) beta product key from here. You can also try out other product keys, if you have one. The existing RC1 beta product key used to activate Windows Vista is may has been blacklisted and banned by Microsoft already. Once generate and obtain the new product key, note it down.
    3. Restart computer and boot into Safe Mode.
    4. Launch Windows Explorer, go to Folder Options and check (tick or select) “View Hidden Files”. Then click OK.
    5. Ensure that you have full administrative access or full administrator rights. Turn off UAC is needed.
    6. Zap the WPA encrypted store by deleting the following files (hidden by default unless you show hidden file as instructed above):


    7. Reboot the computer and log on to Windows Vista normally.
    8. After you logged in, you will likely in RFM mode, with message of “There has been a change to your Windows Activation Process”, and requires you to activate Vista again or restart, with 2 options of either Validate Windows Online or Close.
    9. Click on “Validate Windows Online”, system will still prompt you with error message “Your copy of Windows is not genuine”, and return to the previous screen with 2 options again.
    10. Manually restart the computer.
    11. After the reboot (and login to Vista if applicable), system should prompt “There has been a change in the Windows product key”, and pop up a window for user to type in Windows Vista product key.
    12. Enter the new Vista RC1 product key.
    13. The Windows Vista Ultimate edition should be activated again.
    14. Remember point 1 above, turn off Automatic Updates now, and check out what is the updates before installing. Note that this method doesn’t remove or uninstall KB929391, but should works to make your Vista as genuine again.

Note: If you go to Genuine Microsoft Software website for validation, you will get validation results of “This copy of Windows does not pass genuine validation. The Windows product key installed on this computer has been blocked.”

You can now also permanently activate your Windows Vista with StopTimer.sys hack.