|A PS/2 keyboard that works with other computers should always work with your computer before Windows loads. The hard drive doesn't even have to be installed. E.g. you should be able to get into the bios Setup, no problem. |
Are you sure you're plugging the keyboard into the right PS/2 port ? Usually it's purple.
If your mboard is okay, the only reason a PS/2 keyboard would not work is your power supply is failing and is not putting out +5v.
A USB keyboard should work too, if the bios Setup has Legacy USB devices enabled, or similar, and the USB controllers are enabled there - in fairly modern bioses both are enabled by default - however it's possible, but extremely unlikely, malware could disable those. USB also requires that the power supply is putting out +5v .
Can you borrow a power supply from another computer and try connecting that to yours?
Some mboards develop this problem - electrolytic capacitors were installed on them that were not properly made, and they fail eventually - the mboard manufacturer didn't know they were improperly made at the time the mboard was made.
Open up your case and examine the mboard to see if you have bad capacitors, and/or other findable signs of mboard damage .
This was the original bad capacitor problem - has some example pictures.
History of why the exploding capacitors and which mboard makers were affected:
What to look for, mboard symptoms, example pictures:
Home page that site
- what the problem is caused by
- he says there are STILL bad capacitors on more recent mboards.
Pictures of blown capacitors, other components, power supplies, Athlon cpu's, etc.: