When you enter your system setup utility (BIOS), does your keyboard and mouse work.
re-setting you BIOS using the method I described above will almost always necessitate your going into the BIOS, setting the date and time correctly and maybe choosing to "Load Defaults" or "Load System Defaults" or "Load Optimized Defaults" depending on the wording.
IF you are using wireless input devices you may need to substitute a wired keyboard and mouse temporarily and if it is a very old board you may have to enable legacy USB, which is a setting on some very old motherboards.