McAfee/Norton conflict

I have a new HP Pavilion with Windows 7. It came pre-loaded with McAfee, which I don't like. I tried to uninstall it and download Norton, but I get a conflict. I downloaded Norton anyway and every time I try to delete McAfee I get a pop up saying I don't have proper administrator rights. I'm logged in as administrator, so...I'm not sure what's wrong.

I've searched the forums and the only solution I've found so far won't work. I can't uninstall the LiveSafe from McAfee.