Certain changes in BIOS settings—especially timings, voltages, or frequencies—can cause the computer to no longer boot.
If you are still able to enter the BIOS setup, reset the BIOS to the factory defaults:
- Press F2 during boot.
- Press F9 to set defaults.
- Press F10 to save and exit.
If you cannot enter the BIOS setup during boot, follow these steps to clear the CMOS:
- Turn off all peripheral devices connected to the computer.
- Disconnect the power cord from the AC power source.
- Remove the computer cover.
- Find the battery on the board.
- Note the orientation of the and – on the battery, and with a medium flat-blade screwdriver, gently pry the battery free from its connector.
- Wait one hour, then replace the battery.
- Replace the computer cover.
- Plug the computer and all devices back in.
A BIOS Recovery can be required after clearing the CMOS. This can clear the CMOS, even if there is no display on the computer.