What OS do you have?,if you have any version of windows then you should uninstall Norton (since it's a very trigger happy anti-virus) and install Microsoft security essentials.

Right clicking the Norton icon in the systray (the area near the clock) should popup a menu in which there should be something like "Disable protection", I don't know because I don't have it.
Anyway are you sure that your PT doesn't have any viruses? Where you downloaded it?

P.S.

DCBloodHound:

What OS do you have?,if you have any version of windows then you should uninstall Norton (since it's a very trigger happy anti-virus) and install Microsoft security essentials.

Obviously it's Windows because Norton only works on it, and Linux doesn't even need an antivirus.

EDIT: Tried on my mother's PC, Win 7 with Norton updated 2011, doesn't delete it

I wouldn't depend on the windows shipped anti virus, it can get very nasty or atleast annyoning.

i have windows security essentials and i hardly notice it.it also doesn't give as many false positives as other anti-virus software.