Hi, Ok where to start... First, about a week ago I upgraded my graphics card, motherboard, ram, cpu and power supply to the following (same hdd etc.): (using xp sp2) 1 x ASUS P5LD2 SE R2.0 i945P Socket 775 6-channel audio ATX 1 x MSI 8600GT Silent edition 256MB DVI HDTV PCI-E 1 x Extra Value 1GB DDR2 667MHz PC2-5400 240pin Extra Value Ram 1 x Intel Core 2 Duo E6320 (1.86Ghz) Socket 775 FSB1066 4MB Cache Retail Boxed Processor 1 x Extra Value Gold 600W 12cm Fan Silent PSU - PFC 20+4pin I reformatted ofcourse. Everything seemed to run fine but I noticed that after about 30min of gaming the gfx card would freeze for a long time or I'd need to reset. I then noticed it seemed to happen when I would start a game, close it down, start it again then it would usually freeze again (so i assume not overheating since in total it would of been running for like 5min). Anyway after trying rerformats to vista/xp etc heres what i found: Vista + latest drivers i get "Display driver nvlddmkm stopped responding, but has succesfully recovered." XP + nvidia site version drivers (i.e. non-beta) i get freezing + eventual crash saying something about nv4_mini.sys. XP + beta drivers i get just freezing. I put the card in my friends PC and that seemed to run fine, bizzare. A few days later i RMA'd the card and asked for a 2600XT in return (didnt know what else to try), they said they found a problem with the card and they sent the 2600XT. Again all went fine for about a day... then i notice colours starting to go crazy. After about an hour no game would run (crazy colours followed by VPU recovery). So I thought I'd try it in my friends pc again, once again it runs fine. I pop the card back in my PC and it runs fine again !?!? well at least for a day... then back to crashing. So now im guessing its a hardware problem either ram or motherboard maybe lose connection or something... Anyway i tried this: start a game, ofc it crashes etc.. reformatted my pc, latest drivers etc. install game, runs fine..... Now I'm totally puzzled to whats wrong... If I look at the individual problems i seem to come to different conclusions: vpu recover / odd colours -> gfx card/drivers problem? pop the card in and out fixes it -> lose connections? reformat without taking the card in or out fixes it -> software/drivers? I'm tempted to RMA the motherboard :S Forgot to add: I install xp with slipstreamed SP2, intel chipset drivers, new ati drivers, latest driectX, few games and steam (HL2) always when I've been reformatting.