No virus found......is it a good thing? :o)

Good day. I have Symantec antivirus corporate edition installed on my work computer.  It never finds any viruses/spyware on my computer while my home computer does.  I do have a Norton product on my home computer, not sure which one it is.  Maybe I am a little paranoid, but I figure that I use the same websites so if one computer has an occasional virus then why doesn't the other.  Occasionally on my work computer, I get a box that opens up after an update.  It says that it is the Antivirus repair wizard and asks if I want to repair the infected files in the Quarentine.  I always say no.