Hey people, I have this problem & needed advice. I have this computer, a Celeron 500 MHz, Mercury motherboard, etc. Since today morning its starting up automatically, that is, I don't even have to press the power on button. I just turn the electric switch & it starts up. It detects the hdds & cdroms & then says cmos checksum error & stops booting. However, when I go to BIOS & restore the default setting, save & restart, it starts up fine. What the hell could be the problem. Its pretty clear that is not a software problem of any sort. I checked out that the CPU fan is busted & needs replacement. Thats a problem for sure, that explains the constant freezing also, but is there anything that I should be checking here?. I mean should I try replacing the SMPS too?. I mean why is the system starting up on its own???. Please help & give me some advice.