Check these three things:
1 - Make sure the mouse and keyboard connections are correct. Many times plugging in a PS2 mouse in the keyboard connection makes the computer stop with a keyboard problem. If you are using a USB keyboard, make sure the PS2 keyboard option in the BIOS is disabled or set to ignore.
2 - Make sure none of the key are stuck. If one of the keys is stuck - like it's being pressed - the computer may stop with a keyboard error.
3 - If the keyboard has an actual LOCK key button or switch on it, unlock it.
You can also try another keyboard - just in case the one you have is faulty.
