Can not uninstall Norton Internet Security 2011

A 60 day trial version of this program was pre-install on the computer when I purchased it.  I never activated the trial version because I have been using Comodo products. Comodo failed this week and will not reinstall.  I purchased MacAfee Total Protection 2012 and attempted to install.  It detected Norton and attempted to uninstall.  Norton will not uninstall.