mmm6075

Hello.
My system is about 4 years old. Over time I have replaced parts as they have died.
I started with a AIW 9700Pro, which died afier about 2 years. I got an RMA from ATI, and they replaced it with a AIW 9800Pro.
A few months ago, my power supply,Mobo and chip died (KT4VL/AMD XP 2400)
I had them replaced in the shop with a AMD Sempron 3000+ and an MSI K8MM-V, and a new ps.
I was able to play games like the Movies, Pirates!, and NWN. Recently I bought Galactic Civ 2 and while playing it, my computer got hot and shut down. It was down for about 30 minutes before I could turn it back on. It worked ok after that, but my internet seemed slow and I had a lot of old programs, so i reformatted the HD.
I reinstalled all the latest drivers, including the latest Catalyst drivers. My computer will work fine for a bit, and then go haywire and say that the vpu recover would sya that my card was rebooted because it had quit responding.
I uninstalled Catalyst (following all ati's instructions and deleting old versions) and went to an older driver that had just the vid card driver and none of the extras that come with the AIW. (All I want to do is play games and surf the net).

I had a couple of windows running on the net, and a video, when the screen went dark.
The monitor would go to sleep and then on, but the screen stayed dark gray.
I re-styarted my computer and it has been Ok since. I haven't tried installing or playing any games yet.
I do not know what is causing this. Is there a way to test my card to see if it's going bad? Am I missing a driver? I just don't know. Any help would be appreciated.

-Mike

H3X4D3C1M4L

What kind of power supply was put in? If it was a noname PSU I bet that's the issue