It started happening since 3 months ! I have tried TdrDelay with regedit dword 32 bit to 8 and 2 , regedit Qword 64 bit to 8 and 2 . I also used Display driver Uninstaller and rolled back drivers (also the one given with the card) using clean installation ! But nothing has made it right ! Please help if there is another solution ! I use windows 7 64 bit !