sygate removal

Trying to install comodo 3 and an old Sygate firewall was found that I had removed through add/remove programs. How do I get rid of it 100%? I tried regedit and when I try to delete keys I get an error message about unable to delete , I am the computer admin.

I downloaded the last free version of sygate, installed it, turned off the firewall, removed with add/remove programs, rebooted and I was able to install V3 :■■■■ :■■■■ :■■■■ :BNC