got a problem with my folks desktop PC, its about 6 yrs old.
occasionally i'll get cmos checksum error - i originally thought maybe just cmos battery, but sometimes it will go further & BSOD when loading windows "pc has encountered a problem and will be shut down to prevent damage". other times it will just freeze when loading windows, mouse & kb unresponsive.
it fails 100% of the time lol, never actually makes it into windows 7, whether in safe mode or not. last full hdd scan was maybe 6 months back, no bad sectors.