Removal of Norton Anti. 2004

I just got my home computer hooked-up to the internet today after laying fallow for a while. Since the last time I was on the internet with this computer Norton Antivirus 2004 has expired. Now, I can’t uninstall the program to use another. An error stating “A NIS account with supervisor access must be logged in to unistall this product.” I can’t even renew my subscription to activate the program. Is there anything I can do to uninstall the product.

Thank you for your help!