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 your 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.
cheers
Romanus



May 13th, 2008 at 4:49 pm
Please follow next link for complementary info.
http://technet.microsoft.com/en-us/library/bb932139.aspx
May 17th, 2008 at 2:11 pm
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