Well, well. Today after dinner, I was hoping to get a good round of Counter-Strike in. So, I launch Steam as usual, and connect to an fy server just for fun. After about a minute at this fy server, the computer hard-locks. Vertical lines up and down the screen, and then after a few minutes the screen goes black then gives me a wierd message that I forget. So, I restart and try again. This time the computer hard-locks after about one minute. The next time I try, right when it's done connecting. My brother says this happened to him once yesterday or a few days ago, but he just restarted and it didn't come back. So, I uninstall my Catalyst's completely, run driver cleaner, and then install the 4.1's. Restart, try again, and same thing. After restarting from the crash, I try to run Halo, and the same thing happens before I get to the main menu. Same thing with Unreal 2003. Turns out that all of my games are doing this! I checked my power supply voltages, and they are alright. I made sure that the fan on my video card was still spinning. My computer never did this before, and the last thing I need is another headache with it. Has anyone else had the same problem? Or would care to explain to me what the hell is happening? Oh yes, the system I'm running is in my signature. Please, before I go insane over another problem, someone help. 
UPDATE: It turns out that Call of Duty didn't crash when I played it for a few minutes.
UPDATE: It turns out that Call of Duty didn't crash when I played it for a few minutes.