I'll try to give as much info as possible as this seems a bit serious. Yesterday, i installed a new cooling system on my GPU. an EAH4870 (old, i know). My previous one, with which also i upgraded the original cooling system, was working fine, except for the increasing noise due to one fan slowly failing and causing a lot of noise. So i installed the new colling (a decent one by Zalman) without any problems at all, and proceeded to playing quite a few hours of SWTOR with 0 problems. At some point, some 4-5 hours in the game, i got a sudden black screen, screeching sound and an out of range signal message from my monitor. Reseted the PC, which booted normally, and did not start the game again. I got a movie playing in fullscreen and some 5 minutes later, the screen froze, screeching sound again and that was it. No black screen or out of range message this time. Shut down the PC and didnt turn it back on. Now, the first thing i thought was that i somehow screwed up on the cooling instalation so i opened the chasis and checked the GFX card temp. By hand. It was barely warm. Remember that i had been playing SW for HOURS! And thats it. PC still works normally, I turned it on this morning for about 10 mins. Didnt try any VGA taxing tasks though as I didnt have the time. Things to note: I also installed an extra 4Gb of RAM yesterday. Identical to my previous RAM. The PSU is a new one (Thermaltake) 550W. The cooling system came with an outside fan controler which i also installed, even though it can be ignored. Had it running on full speed anyway the whole time as it doesnt realy make any unwanted noise. So, any ideas what could have causedd that hang, and any way to avoid it happening in the future? Thanx all.