Keyboard just bleeps

[#1]

IBM Powermate 250
Windows XP
PS2 keyboard
When I turn the machine on it boots up as far as Windows Password nd when I try to enter the password it only beeps, Nothing else happens. I cant type any characters at all.
Same problem in safe mode and same problem with a different keyboard.
Can anyone please advise possible causes and solutions.
Thanks

[#2]

If you can get to Safe Mode, then this suggests that they keyboard is working - or at least your F8, cursors and Return keys are!
Does your mouse move when you're on the windows password screen?
Can you click on other profiles or get the computer to shut down?

[#3]

Try a USB keyboard?
Try keyboard on another PC to ensure it is working.
Try disabling USB Mouse Support in BIOS.
Does anything here help:
http://support.microsoft.com/kb/258826
Any problems in Control Panel-System-Hardware-Device Manager
Regards,
Neil