If you think it is overheating, open the case up and put an external fan on it. If it takes longer to BSOD, that might be an indication. If the system has overheated in the past, possibly some damage was done and causing part of the problem. If you changed cards and still got the blue screen, possibly it is the driver installed causing the problem. When you uninstall a driver you have an option to uninstall all variations at that time. If you haven't done that, you might try. I am still not convinced the sound is not involved. Can you turn that off in the bios for testing? The GTX 480 is a good card and was the top of the line last year, or so. They do get quite expensive, but I am not familiar with your GT 120 card. The manufacturer of the card might make a difference as they will use different cooling options and some software and card differences. You might try running the Driver Verifier. Check the link for instructions, but make sure you note how to turn it off (verifier /reset) and be able to boot into a command prompt, or possibly safe mode so you can. If the verifier causes a blue screen at boot, then you will have to disable it prior to getting back in your system. If you have specific questions about this, post back. I really can't think of something else for you to try. Test the system with the most basic setup you can get and see if anything influences the bluescreens. Maybe post another dump file after you make a change to see if anything is different.