Shut down the computer
Unplug the power cable
Remove the laptop battery if applicable
Press and hold the power button for 10 to 15 seconds
Open the case or access the motherboard
Locate the CMOS battery
Remove the CMOS battery
Wait 5 to 10 minutes
Reinsert the CMOS battery
Reconnect the power cable
Reinstall the laptop battery if applicable
Turn on the computer
Enter BIOS or UEFI and reset settings if needed