My specs:CPU: QuardCore AMD Phenom II X4 Black Edition 965, 3415 MHzMainboard: M5A78LLE ASUSRAM: 8 GB RAMGPU: Sapphire Tri-X R9 290Power adapter: SF-550P14HE 550W 230V onlySystem: Windows 7 Professional So, whenever I use my Sapphire Tri-X R9 290 my computer crashes absolutly randomly (playing games, using windows, whatever, even if I do nothing): So, here are the important parts: I previously had the exact same error with a Powercolor R9 290, what I tried: - removing all drivers that could cause the problem - updating my mainboard BIOS - trying multiple drivers and AMD catalysts - testing my RAM and CPU - Windows reinstallation - many other things I don't remember anymore This problem does not occur with my Sapphire Radeon HD 6850 and the weird thing is, I can play games on ultra (with the new Sapphire Tri-X R290) and it doesn't crash. Then, I go do something in Windows and it crashes, it is absolutly random... sometimes it crashes 1 minutes after boot, and the next time it may crash 20 minutes after boot. When I sent my Powercolor R9 290 back, they told me that the GPU was absolutly fine and worked 100% when they tested it. I really don't know what the hell is going on... I tried to find a solution in the internet, I tried everything. The next thing I'll do is replacing everything (Mainboard, CPU etc.). But it will take some time until I can do that, so fixing the problem now would be really good.