cant install the free firewall

i installed the comodo free anti virus first and realized i need the firewall, not the antivirus.
i uninstalled it and restarted then downloaded the free firewall, but apparently, it wont allow me to install it and says i can’t install it because there is a previous comodo installation.

can you help me install it? like i said, i already uninstalled the free anti virus.

You could try this: Comodo Forum