I've a useful tip for those that still do fresh installs of Windows XP.
A majority of large enterprises still must use Windows XP for a multitude of reasons. If you are in I.T. in such an environment you obviously find occasion to install Windows XP on a new PC. Even if you are a home user you may still use XP and have to do a fresh install. This will help you.
During the last week or so it seems that MS has somehow managed to break Windows Update on fresh installs. I have a XP Pro w/SP3 CD that I install all builds with. (Enterprise Licensing). After the install when I try to run Windows Updates I will be greeted with a KB article stating that you must have XP SP3 to use Windows Updates. Even though I already have it installed it refuses to go further.
Well, the solution is to download the appropriate version of the Windows Update Agent. It can be found here: http://support.microsoft.com/kb/949104
After installing, reboot your system and Windows Update should work as intended.