keyboard prob ibm s51 when booting up.

without the keyboard (usb) plugged in, there are 2 short beeps shortly after booting up. then it says mouse initialised
ERROR
keyboard error

once the windows xp screen comes up, then i have to plug the keyboard in and it works ok. but if i turn the comp off, leaving the k, board still plugged in, then boot up again, all i see is a blank screen with a - sign flashing in the top left corner of the screen. any feedback would be appreciated.

Well since the computer halts on boot-up, the obvious place to look is in the BIOS settings. As I recall, some older BIOSs let you choose whether the computer would accept a USB keyboard/mouse or not. My guess is that your BIOS is set to NOT, so the computer halts because it cannot find a keyboard.

I'd go further and say either the keyboard - or more likely the USB port - is faulty

Try the keyboard in another port, and also try another keyboard