I would like to make an announcement for Sygate Personal Firewall users who are trying to install Comodo Firewall.
You MUST uninstall Sygate before installing Comodo firewall. Otherwise you will lose all your internet/network connectivity.
Disabling Sygate does not work. Because Sygate Personal Firewall hooks your TCPIP.sys file and stops all your internet conection.
NEVER install Comodo firewall while you have another personal firewall installed, even disabled.(including but not limited to ZoneAlarm, Outpost, Kerio etc.)