It's been a while since I've posted any problems here, but this one has me dumbfounded. I've been running Windows Vista Ultimate since it went RTM in November. It's not a beta. I got a comp copy from MS for beta testing and submitting bugs. Everything was working fine until about a week ago. Here is the progression of problems. First, I installed the new Nvidia drivers (158.18) for my GeForce 6600. I didn't have time afterward to test the performance of the drivers in 3d apps, but found out the next morning that there was some incompatibility with it and my TV Wonder 650. When watching TV, frames were getting "dropped". Before I had a chance to uninstall the drivers, my wife did a system restore. Things have gone downhill from there. I had numerous blue screens seemingly at random times. I eventually got to a point where I booted to safe mode and even blue screened there. This would seemingly isolate the drivers as being part of the issue. At this point I booted to BIOS to check temp settings of the CPU. My AMD 3200+ XP was running at approx 178F. According to AMD's website, the max temp should be 185F. Without knowing it, I may have hit this limit again and again during those numerous BSOD's. I went out and bought a HSF and put it on. Thinking I had the problem taken care of, I went to boot. Now I can't boot at all. If I try to boot into Vista, I get past the screen where I can choose safe mode or whatever and it starts to go and then restarts...as in restarts back to video bios and all that...a hardware restart. I've tried putting in a different hard drive and installing Vista on there, it gets through the initial "Windows is copying files" with the progress bar on bottom and when it completes..nothing. I've tried Seagate's Disc Utility program, which tells me it installed the drivers for the CD Rom drives and then...nothing..just sits. I've tried removing my ram and just moving one stick through the 3 slots available. Same result. I have another PC in the house with similar specs so I can swap parts in and out, but this could take forever. I am starting to think that the CPU fried and it may need replacing, but I am not sure. I'm just looking for input here. Depending on where you look for troubleshooting tips, some people say bad ram, others bad PSU, others bad CPU, and even other bad MOBO...the only reason I'm leaning towards the CPU is that it only starts to show problems now when it has to do some processing. Basic BIOS and basic startup work fine and memory test fine in BIOS. I haven't run any extensive memory test on it since the failure, although the memory tested fine before. Thanks in advance for the input. Specs: ASUS A7N8X-E Deluxe AMD XP 3200+ 1 GB Corsair Not sure what else to put.