My System: - E8500 CPU - 2 * 2GB G.Skill DDR2-800 4-4-4-12 - Asus P5N-D MOTHERBOARD - 2 * XFX 8800GT 512MB xXx Edition - Thermaltake Toughpower 750W - Windows XP Pro x64 I’ve been having this problem while playing avi video clips (divx etc.) "sometimes" it would screw up and all these colored bands start appearing, like artifacts and vertical bars etc . And my mouse cursor turns into a big smudge. See attachment. I don't think this has to do with heat, just playing a video clip doesn't put the system under much load at all, everything running at idle temperatures. It also doesn't crash, it would happily keep playing (with colors and bars and all.) But when I do launch another application that uses 'graphics' that's when it will freeze and hang. So, say, after having this happen, I could still continue browsing, moving around the desktop, everything is fine. (Except mouse is a smudge.) But as soon as I launch anything that's 'graphical' it will hang. e.g. (start any game, launch a screen saver, rthdribl.) and I have to reboot. I don't know what the problem is. It only happens sometimes, for example I could play a clip all day long and it would be fine. It happens with multiple different files, all of which I have viewed on another machine and seems to be fine. It would ‘turn bad’, and I would reboot and jump straight to the location in the file that it happened and it would be play fine. The same thing happens with different media players I tried wmp, vlc. Aside from this, the computer appears stable enough. It passed an 18 hour ORTHOS run, 10 hours of MemTest86+, no errors. I tried going back to another set of drivers. I was using 169.32 drivers. I tried going back to 169.21, it didn’t help. Running out of ideas… what could it be? Codec? 64bit operating system issues?