Windows updates fail after upgrade

I have just upgrades a PC at work from win2000 to XPsp2. The upgrade was done by inserting the XP disk while booted into 2000. Upgrade of software and hardware went fine. Only issue is now windows updates fails after upgrade. Both auto updates and Microsoft update site fail. I can download and install updates manually. The errors are;

0.719: KB927779 Setup encountered an error: The update.ver file is not correct.
0.875: Update.exe extended error code = 0xf201

This is the same for all updates.

Any Ideas?