Windows XP SP2 hangs at agpcpq.sys in safe mode

I have a Dell Dimension 4700C with Windows XP SP2. I tried to boot this morning normally, but I received the XP splash screen and then it went black (no blinking cursor). I then tried safe mode, it hung at agpcpq.sys. Then I tried, last known good config. That WORKED!! I thought I was home free. Tried to reboot and same problem. Next, I tried the Windows XP Reinstallation CD from Dell. It looked like it was working until the screen said “Windows is starting” and froze at that point. I also reseated the RAM.

Any thoughts, suggestions, advice?

Thanks for listening!