• A #1 or #2 Phillips-head screwdriver, or (less likely) a T-15 TORX driver or a 1/4" hex nutdriver, to open the case
• Needle-nosed pliers if you are working with jumpers
• A small flashlight or headlamp

With tools at hand, perform the following steps:

1. Turn the PC off (this means a total shutdown, not merely standby or hibernate mode) and disconnect the AC power cord.
2. Remove the cover from your system (this step may require tools, undoing a thumbscrew, or flipping a latch or two).
3. Refer to the user manual for the motherboard to find out how to "reset CMOS" memory. You may also find a label for specific jumper or switch settings marked on the system board.
4. Change the switch setting or jumper position to a specific position or remove the jumper entirely as prescribed in the manual to clear or reset the CMOS memory.
5. Wait 20-30 seconds for the memory to clear out from lack of power.
6. After 20-30 seconds put the switch or jumper the way it was before for normal use.
7. Reconnect the power cord and start up the system to see if the settings have changed to defaults.
8. Shut the PC down, disconnect the power cord, replace the cover, reconnect the power, and power up the PC.
9. Enter the BIOS setup program to configure the system as needed. This may include setting the date and time, selecting disk drive parameters, and selecting which devices the system uses to boot up with first.