Save any important work if possible
Shut down the PC
Unplug all external devices except keyboard and mouse
Disconnect the power cable
Remove the battery if it is a laptop with a removable battery
Press and hold the power button for 15 to 30 seconds
Reconnect the battery if removed
Reconnect the power cable
Turn the PC back on
If needed, use the motherboard reset button or clear CMOS by removing the CMOS battery for a few minutes
If the PC still does not respond, contact technical support