My comp recently started rebooting when I play games, but only when I play games. It started with Oblivion and Legacy but now it does it with FFvTTR. I am thinking my PSU is failing. I have a Ultra 550 and was told on other boards this is not a good power supply. What do you guys think?
Sounds like you are running a hot system, and I dont mean it as a compliment. ;)
Im really no computer expert but there's a possibility that your heatsink on your processor was not placed correctly or that overall you just dont have enough cooling going on. In other words I think your computer shuts down to keep itself from melting when taxing itself too much.
I would have to agree with the above - either your cooling system for your cpu or vid card are dying, the power supply is dying or your case itself is not properly vented.
If it is overheating, you will be able to test it by removing the cover and blowing a fan into it while you play cpu intensive games. If it no longer craps out on you, you can pretty much bet your cpu is overheating.
There are some motherboards that have a tempurature monitor in bios as well... there are also freeware programs you can DL that monitor it as well - the names, of course, escape me at the moment....