Last night....I had to reboot....[it happens]...
When I did my keyboard failed to be 'seen' in windows....aka...I couldn't type in my logon pass. [there was no 'flash' of KB lights, though the numlock light was on].
If I then tried the caps lock or similar...it'd cycle once or twice then fail to respond....[mouse worked, though].
KB was fine in boot/bios...only stopping in 'Doze.
It gets stranger....
Tried another KB...also PS2...also no luck.
I have two HDs...same OS...both in caddies...other is simply 'older'...did a swap....and here I am...obviously working.
Did I mention 'stranger'?
Tried a re-install of XP via the CD....that was fun....till it asked for the CD Key....yes, you guessed....
I did a Drive-image restore that was about 2 days old....overwriting the original 'C'....and rebooted.
Nope...same thing.
I have another Image...about a week older...maybe worth a try....next 'option', perhaps.
Only theory I have is either it's a low-level bootsector virus halting keystrokes [bit far-fetched] or it's a physically damaged HD 'sector' that just happens to be where the PS2 or keyboard registry/drivers/files is located...and an image overwrite still hits the same data on the same bad 'sector'....equally far-fetched.
I really don't believe the image could have had the same issue [as software error]...but I guess it's possible.
One quaint idea is to try a USB keyboard...and see if 'Doze can notice the change and respond correctly [but I don't have one - yet].
The upshot of all this....no matter how clever you think you are with backups, etc...when Windows has a brain-fart and won't even read your keyboard....you're well and truly knackered....