Okay, here is a problem that has been giving me a headache for about 8 months now. Here are my PC spec's before I go into details. OS: Windows XP Version 5.1.2600 Service pack 3 Build 2600 Mobo: MSI K9N2 SLI Platinum Ram: 4GB Hard Drives: 149 GB and 115 GB GFX card: NVIDIA GeForce 9800 GT Processor: AMD Athlon 64 X2 Duel Core Processor 5200+ 2.6GHz Power Supply; 850 Watt Okay, here is a description of my problem. Then i will tell you what I have done thus far. When I built this PC, I was playing games such as Enemy Territory QuakeWars with no problems, then I bought COD4 and for about 4 months I had no issues. Then I started having random crashes in the middles of the game. What I mean by crashes is the game would lock up, the screen would become distorted, and the sound would loop at a very high rate and volume louder then it should be, and that would last for between 3 - 10 seconds, then the that was it. I couldn't do anything. Only thing I could do was a hard shut down and restart. It only happened with COD4, but none of the other games I played. Well, after talking to one of my PC guys I am friends with, we started a check list of possiable errors and asked over at the IW forums about this to see if anyone else had this issue. Well we ended up testing the power supply and that was confermed that it was starting to go, so I upgraded it from a 700 watt to 850 watt and then upgraded my graphics card to a 9800 GT to replace the 8600 GT OC I had. Went and played and I went about 3 days with no crashing then it did it again. This time we looked at the RAM and removed them and ran each individually and then ran MemTest to test the ram. Everything was good. After that we looked into the HD's so we used another program to test the HD's and everything checked out OK. Then we tested the CPU and everything looked right. Now I bet your thinking, did I check if I had the drivers up to date. The answer is yes, I went and upgraded all the updated drivers, (still wishing there was a program that could detect what drivers you need and fetch them for you). Then we though it could be a faulty GFX card, which got me wondering why only COD4 and now QuakeWars or FrountLines, Fuel of War. But I ran the GFX testing program that came with Nvidia and everything checked out okay. I have uninstalled and reinstalled COD4, I also have reinstalled XP with still no luck. I am not sure where to go from now. Sometimes I can play 3 - 6 hours with no problems, and sometime I can only play 10 min before it crashes and locks up. Any Idea's?