Visit Symantec's Security Response and let them scan the machine. If you're getting the message that these things are "in use" then you can pretty well figure that they're busy with malicious activity. See if Norton can repair or quarantine the programs or files.

You might have to open the computer in the "Safe Mode" in order to delete the files that are the problem. If you're not sure about what is on them and think they are repairable (but you should have a backup so these can be deep-sixed) then burn them to a CD and delete them from the machine. Look at them carefully later, only after the virus has been removed or disabled, and only if by looking at the titles of the files you think it's worth the risk.

SRS