I don't know of any virus's that would cause this but it could be done.
First I would go into the BIOS and check to see if the parallel ports are not disabled.
Second I would go into Control panel and click keyboard to see what is being used and if there is a problem.
You will have to change the keyboard momentarily to the PS/2 port but not the mouse.
You will need that to move around. Find out if the computer sees the keyboard and what type.
Report back with your findings if you don't fix it.
To me, it sounds like someone is playing a prank on your friend. I never heard of just the PS/2 ports going bad on a motherboard.
Your Hardware Guide.