OK, you need to reset CMOS.
Your mobo manual will usually detail how to use specific jumpers on your board to reset CMOS. Computer must be unplugged from wall outlet.
Lacking that, you can carefully remove the CMOS battery for a minute or two and then replace.
The computer must be unplugged (wall outlet) and you must ground (earth) yourself before touching anything on the mobo. Use a grounging wrist strap or touch the computer frame or power supply case while unplugged from wall outlet.
Temporarily removing CMOS power will return the computer to safe, default BIOS settings. You will probably have to go through all your BIOS settings to return to optimum settings.