Did your previous version uninstall completely? Were there any remnants?
Comodo sometimes leaves behind registry entries such as the installer startup entry here:
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
and the older version left Event Viewer such as this one:
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\EventLog\COMODO Internet Security CEF
The Beta left behind a couple of drivers, at least on my system which I had to manually remove. Run CMD as Administrator, type Dism /online /Get-Drivers /Format:Table
and then remove the two listed by entering the below, replacing the ?? with the oem number.
pnputil /delete-driver oem??.inf /uninstall /force
and restart.
The installer can take a minute or two to start up CIS/CF once you complete the installation process but will then show to either do a quick scan and then prompt you to restart or if just the firewall, show the main UI window and offer you to restart the machine to finish the installation.