Log on error after upgrading AGP drivers

[Guest]

I upgraded my AGP driver for my VIA chipset following manufacturer instructions as the first step before installing my new ATI Radeon 9600 XT Video card. No error messages during this process, but now when logging onto my user account (or any other for that matter, even a new account I just created) I get a Windows Product Activation dialog box with this error message: "Some system files are missing or damaged. You cannot log on at this time. Please use your installation CD to reinstall or repair Windows. Error code: 0x80040507." Can't find this in the Knowledge Base.

Any ideas how to avoid reinstalling Windows XP? I have tried both system restore and reinstalling old AGP drivers and still get the error message. I assume a windows file must be corrupted or missing, but don't know which one. I am able to get in under Safe Mode, but not with last known good version.

 

[LuDean Marvin]

I had a similar problem installing my Radeon 7000 AGP video card. When I
returned from restart, the sytem insisted on rebooting, adfinitum, just
before the Windows Splash. I tried safe mode, but the same thing. I
finally had to perform a repair install from the WinXP CD to cure the
problem. Sorry I don't have any good news.

LuDean