Question : Problem: Mystery compatibility issue Monitor and PC

Does anybody out there have any suggestions?

BACKGROUND
My Client called me in because his PC had turned off unexpectedly. He had also had video problems previously. He diagnosed an overheating issue, so he cleaned out the inside of the tower. Unfortunately he took the CPU and fan apart, bent the pins and therefore one dead CPU.

We were able to replace the CPU and all was well so far. Device manager told me that the video driver was not the correct one although seemed to work. I updated the driver, disk clean up, chkdisk, defrag, windows update, bench tested (connected to one of our monitors) for 24 hours - all OK so returned PC to site.

PROBLEM
As soon as I connected up the Reegen monitor, Windows XP refused to start. In safe mode I uninstalled the video driver and rebooted into normal mode. Booted in Windows but the resolution would not go above 800 x 600 with a 4bit quality. I tried 3 other drivers (various ages) with basically the same effect.

However when I disabled the video adapter, strangely everything worked smoothly with the native resolution 1280x1024 and 32bit colour. I then tested the monitor on a 7 other PCs and with only one exception, everything worked correctly. I also tried the PC with 3 other flat screen monitors and all OK with the adapter enabled.

So to sum up the driver is good, the monitor is good. But when they come together they go bad unless the adapter is disabled. Bear in mind they were bought as a system from a shop which built the PC and have worked together for 2 years.

I left the adapter disabled and suggested to the Client that maybe the registry was "messed up" (he has used Regcure) and suggested  an XP re-install which he thought he might do himself. However, for my own satisfaction, I would like to conclude it more satisfactorily.

Any ideas?

Answer : Problem: Mystery compatibility issue Monitor and PC

I would also assume something fuzzy happened to your system and if system restore won't fix it for you then yes a reinstall might be needed