Keyboard no longer works when entering BIOS

Solution 1:

try using non usb keyboard, one with PS/2 connector.

Solution 2:

Plug in a PS/2 keyboard. You can then change the setting in the BIOS to enable USB support for the mouse and keyboard. You can then use your other keyboard. If you do not have a PS/2 keyboard lying around, get a USB to PS/2 converter plug it into the PS/2 port. This will help you get to the settings in the BIOS.

Solution 3:

Try using the keyboard that came with the machine (assuming it's a consumer machine). I know a number a of large name brand manufacturers will not support third party or wireless USB keyboards from BIOS screens. But the BIOS will accept input from the branded wired USB keyboards.