My mother has a compaq running windows vista that is a few years old.

Her free antivirus stopped working and she said that she couldn't read her AOL mail and there seemed to be a security problem.

I installed norton antivirus which removed 3 viruses and a bunch of spyware. The machine seemed fine, but when I brought it back to her house the mouse no longer worked. She says she bought a new USB mouse but it still doesn't work. Any advice on what to try ? Do I need to send away for install disks and reinstall everything ?