Well, ask your Administrator to uninstall your version of Norton's
Or, try and uninstall it yourself in Add and Remove programs
It may prompt for a password, by default it's symantec
After you do that, we can try a free version
OR, if you can't get a hold of the Admin anymore, we can go from there
BUT>DO NOT have more than one AntiVirus software running one your computer at one time
Bad conflicts, believe me, I've tried it with 3 different versions before, I couldn't even use my computer till I uninstalled at least one AV