Comodo AV will not install with Comodo CIS installed

I installed the Comodo firewall. free version… its very nice. I like it, but the comodo antivirus somftware will not install, get the Incompatable software warning. saying that comodo antivirus is incompatable with COMODO Internet security… I downloaded both here Firewall Download | Best Firewall Security software for Windows trying to test them out…

Why are they incompatable.

edit: go to Start->All Programs->Comodo->CIS and choose Add and remove components. then select to add AV