Im having this problem for a while now, and I cant seem to find a solution. It takes me about an hour before windows starts, because it keeps on rebooting at the windows title screen. No change for safe mode too. And when hitting F8, and selecting "Last known good configuration". When its been rebooting for about an hour it starts. I have tried allmost everything. I have scanned for viruses. Downloaded a "Sasser worm" remowal tool, but it didnt find anything. I have checked all the cables and wires. I have tried putting in different RAM chips, but nothing. Ive tried deleting the partition and reinstalling Windows, but it reboots during the instalation process. And on the 10th time it was installed. And rebooting the same. When I install Win XP everuthings fine. But my machine is too slow for winXP so i need the 2000. Is it my motherboard or CPU ? :/ Or maybe the cooler ? I have no Ideas. Please help !