I have an older desktop computer running Windows XP, and the keyboard doesn't respond at any point before the Windows logon screen is displayed. I need to reinstall Windows, but I can't get to BIOS or to boot manager. I have tried PS/2 and USB keyboards, with no success.
It was suggested by techie007 to do "hard reset". I thought a hard reset is taking the battery off and putting it back after a few minutes.
I tried that approach and it works. Now the keyboard is responding before Windows boots.