We are providing these links as tools and possible solutions for you
Mozilla Firefox
Avast Antivirus
Lavasoft Ad-Aware
Canfield Consulting's Remote Assistance Tool
Symantec's Security Response Site - For Virus related information
'Let us worry about your computer, so you can worry about the important things.'
Once a year (at least) you should open the computer's case and vacuum out the crud. (If this is worrisome, let a tech do it.)