20" iMac, Intel Core Duo, 1x1GB RAM + 1x512MB RAM, 128MB video card, 250MB HD (about half full). I will do my best to describe a problem that just popped up yesterday. I apologize in advance if I seem to jump around. Yesterday, while playing WoW, I started to get some Video artifacts (diagonal lines of fuzzy colored squares). It would come and go. Later, this problem would fill the screen and would freeze the game (although audio remained). Only option that I seemed to work was a hard power down (hold down power button in the back). Before you say I have a WoW problem, there is more. After waiting 15-30 seconds I hit the power button and start up the iMac. Most of the time I will have similar video problems that will show up as early as the apple loading screen and as late as a minute after the os has fully loaded. Same artifacts and freezing of the computer. After a couple of 'reboots' the problem seems to go away and I am fine doing anything I want. Except play WoW again which starts the problem again. Now I know that WoW can tax my video card and RAM so I have 2 thoughts: 1. I have an overheating video card or a bad RAM module. How can I best test/diagnose this? 2. I need another video card and RAM hog program to test to see if the problem is video related or WoW related (I have done a total uninstall and reinstall of WoW and the problem persists so I dont think it is a bad WoW file). What is another similar hog of a program (that most people have) I would appreciate answers to my questions above, other ideas, and just general help. Thanks in advance.