Cmos checksum bad, cmos date/time not set - press F1 to run setup Press F2 to lo

Did you try updating your bios? Have you tried removing and replacing the cmos battery? What has changed in your system to get you this error? Could you be a little more descriptive with the problem?

time and date are being controlled on the south bridge, the information is stored on ROM cmos chip. you need to replace the bettery, its probably not holding a charge and the information is being reset every thime you get a low current from the battery