You have to clear CMOS on the motherboard without any backup battery OR powercabel !
1. Shut down the pc (if it´s a pc)
2. Remove the powercabel (220 Vor 115V or whatever)
3. Remove the battery cituated on the motherboard
4. There is a set of jumpers (check Your manual for motherboard) ((OPS you just remember that You dont
know where it is !!!))) this URL will leed You to a site that contains a lot
This is another one
Total Hardware 1999
5. Check manual OR homepage for Your motherboard
6. Reset CMOS (normaly You connect another jumper-pair for a second or two and thats why its important that the pc is NO POWER AT ALL !!!!!))
7. Power up the pc again, dont forget the battery.
8. Boot from f ex XP or VISTA CD/DVD and chiose Repair after a few "OK" .
Now CMOS will be reset and the pc is from scratch so let it do it "Auto" so will everything run smothly again )
IF NOT: Repet the abowe steps again (battery?)