Unplug computer and press the power button 2-3 times to discharge residual electricity then plug back in.
Turn on\ the computer by holding the power button down for 20 full seconds then release. Press the Power button one more time (if necessary) to start the computer and then repeatedly press the F10 key to enter the BIOS setup menu. On the BIOS Setup screen, press F9 to select and load the BIOS Setup Default settings. Press F10 to Save and Exit.