I've had Norton Systemworks installed on machines before but never tried to do a scan.
The good news is, if you look at a list of viruses, adware, spyware, etc. such as:
http://securityresponse.symantec.com...efs.added.html
You'll discover Mac and Linux Systems are immune. The only reason at present to have antivirus on a Mac is to prevent accidently spreading them to Windows users.