keyboard(s) not working at all (both usb and ps2)

G'day all, having a bit of trouble here.

Just got my computer back from the repair shop, had viruses/spyware ect...
Went to start it up, and the keyboard (USB) is not working... doesn't respond at all, its as if theirs nothing pluged in. It still works on my other computer however (hence how im here). So i went out and bought another keyboard, this time with a ps2 adaptor. Nope, still nothing. Works fine on my other computer however.

I cant even get into the DOS menu. How can i fix this?
Im obviously going to go back to the repair shop if i cant troubleshoot it myself, however they're closed atm.


Thanks in advance.


Edit: Also, to complicate things, i have a login page so i have no access to my computer whatsoever.