Windows Update "The following updates were not installed"

Referring to the above message windows update might throw at you, it usually (most commonly) happens when you have just installed Windows XP out of an SP2-Integrated CD and the windows update website decides that you need the SP3 Update.

This is caused due to yours wups2.dll file not being registered.

Solution:
1. Start>Run>"cmd" and enter.
2. Stop the Automatic Updates service by typing "net stop wuauserv" (without the quotes of course)
3. To register the dll, type "regsvr32 %WINDIR%\system32\wups2.dll" where %WINDIR% is your windows directory. In my case, it is "C:\Windows".
4. Restart the auto updates service by "net start wuauserv", and either configure automatic updates or point your browser to http://windowsupdate.microsoft.com and you'll be fine.