One more interesting read on Microsoft XP SP3 installation by Mark Dormer, MVP.

Windows XP SP3 breaks Windows Update

If you install XP SP3 on a clean SP2 box, Windows Update will no longer work. Unless you have the newer Windows Update Agent 3.0, you’re stuck in a hole. There is no way to get it via AU or WU or MU; only a manual installation can resolve the issue.

  1. Download the new agent (but do not run it yet) to your desktop (so you can find it below). X86 Version download.
  2. Start, Run, CMD

In the black box:

net stop wuauserv

“%userprofile%\Desktop\WindowsUpdateAgent30-x86.exe” /wuforce (don’t forget the quotation marks)

net start wuauserv exit

The original post.

  1. Chris Warren

    not sure what I was doing wrong but kept getting an invalid file message. I was able to do the stop. Since it wouldnt take the file, I just restarted and am back to square one