For 1-2 years I'd been gaming on my PC 4 hours/day on weekdays, 8+ hours/day on weekends with no problems. Then last summer I'd been gaming almost 14 hours/day on it, and I started getting weird visual errors kinda like this this
while gaming, but I continued playing, then it started freezing while gaming; I assume this was from overheating because the side of the case was hot. Eventually it always had multi-colored dots on the screen, and it would freeze from simpler tasks like web browsing, then it would freeze up sooner and sooner after rebooting. When this happened I had been running Windows XP, so I switched to Ubuntu to see if that would help. I think it ran half decently for a couple days on Ubuntu, it still had the dots on the screen and I couldn't play games or anything but I could browse the web. Then it started freezing again. I turn it on, it has multi-colored dots on the screen, I load up anything such as firefox and it freezes; I can move the mouse cursor but nothing else happens, the clock doesn't update or anything. Did I fry my video card?