How Do I Uninstall Bit Defender Internet Security 2009

I went to Control Panel, and clicked on UNINSTALL Bit Defender 2009. Only, it won't uninstall. When I try to install a new anti virus, it says I already have one installed, which is the stupid Bit Defender, so it won't let me install my new software. Anyone know any secrets as to how to get rid of this worthless thing?