How to Fix Microsoft Update Not Installing Updates or Failed Updates in Microsoft Windows XP


When installing Microsoft Updates in the XP, Windows Server 2003, or Windows 2000 operating systems, a 0x800A01AE error might appear. There are also times when once an update is downloaded it won't install properly, and the update screen shows that the update has failed. Even after rebooting the system and re-applying the Windows Update, it immediately shows that the install has failed. In some cases, the update will install, but Windows will not allow any other new updates to be downloaded and/or installed. This was a very common issue that occured after Windows XP Service Pack 3 was released. However, there is a very quick fix. Follow the instructions below.

Edit: The fix listed in this blog post has worked with many Windows 7 and Server 2008 Microsoft Update errors as well.


You will need to re-register your Windows Update DLL.

  1. You will need to start a Command Prompt. To do this go to Start, click Run, type cmd, and then click OK.
  2. Type the following commands (one at a time)
  • regsvr32 wuapi.dll
  • regsvr32 wuaueng.dll
  • regsvr32 wuaueng1.dll
  • regsvr32 wucltui.dll
  • regsvr32 wups.dll
  • regsvr32 wups2.dll
  • regsvr32 wuweb.dll

You should now be able to run Windows Update again.


Alternatively, if you don't feel like manually typing all these commands out or you need to run this command on multiple machines, follow these instructions:

  1. Open up Notepad
  2. Copy and paste all of the regsvr32 commands from below into notepad.
    • c:\windows\system32\regsvr32 wuapi.dll /s
    • c:\windows\system32\regsvr32 wuaueng.dll /s
    • c:\windows\system32\regsvr32 wuaueng1.dll /s
    • c:\windows\system32\regsvr32 wucltui.dll /s
    • c:\windows\system32\regsvr32 wups.dll /s
    • c:\windows\system32\regsvr32 wups2.dll /s
    • c:\windows\system32\regsvr32 wuweb.dll /s 

    Note a few things:

    • You will need to execute the commands in your %windir%\system32 folder. c:\windows\system32 is the default path for XP.
    • The /s is optional. This executes running in "silent mode" so you won't have to approve every command.
  3. Save your text file as regsvr32.bat (note that you can name this file anything you'd like, just make sure that the extension on the end is a batch or .bat file type)
  4. Put your newly created batch file on your desktop or another easily accessible location.
  5. Execute the file.


If this does not work, Microsoft has recently updated (around June 2011) one of their articles with much more detailed instructions. If the fix above does not work, follow the instructions in this article to completely reset your Windows Updates:


Here is the original article from Microsoft used to create this blog post:, Accessed April, 2006.