after virus removal very very slow

A journalist friend has an AMD 200 which is adequete for his needs of word processing only.
Recently his screen came up with a message to call an 800 number. When he phoned his computer shop they told him it was a virus and to bring it in.
They reformatted and reinstalled Win 98.
The $ 100 bill said only "remove virus" so I do not have any other info on what was done.
He retrieved his computer and the mouse would work but keyboard didn't and loadup was unreasonaby slOOOOOOOOOOOOOw. We even tried swapping keyboards to no avail.In the end we could not find anything wrong and told him to take it back to the shop and not to pay or do anything costly. The only thing they told him was that the keyboard was not plugged in properly ???
got a phone call last night. Keyboard is still not working . mouse is. Computer is still loading Win 98 slow.
Any ideas of what to look for ???

 

Hi.

That problem could be caused by dozens and dozens of things. If you're not familiar enough with the inner workings of Windows I would look for another computer shop. Those guys that did that should apologize profusely and refund any fees collected and reimburse you for any traveling and other out-of-pocket expenses. They should also enroll in a computer repair school somewhere.
Find another shop if possible or find a really good nerd.

PS. All of your equipment is working fine, the problem is in the software.