If a single stick of ddr3 doesn't help, try a completely different stick of ddr3. These boards are very picky about what memory they like. I first tried moving some ddr3 from my Core i7/X58 system into my H55 system. Windows 7 installed fine and things were going great until I installed the graphics driver and switched into 1920x1080. Then it would bsod/reboot anywhere from a couple of seconds to a few minutes. Out of the 6 ddr3 sticks that work great in my Core i7 system, only 2 of them work in the H55 system with any degree of stability. Running memtest86 didn't show any problems, but swapping out the memory is what fixed my stability problem.