I always do a manual install of a new update (why? because I want to have the new install program always available in a certain location).
But in order to install in this manner, the user is required to first manually uninstall the existing version of Comodo firewall (which will involve a reboot after uninstall and then the manual install of the new version).
If you try to run the new uninstall before doing the manual uninstall, you will get this screen:
Many other programs that require an uninstall are able to drive the uninstall from the new install (recognizes an existing install, informs you that old version must be uninstalled first, asks if you want to uninstall now, you reply yes, the old version is uninstalled, the reboot occurs and then the new version install is kicked off on successful reboot).
WHY can’t Comodo do this with their install? This would make for a cleaner install process when doing a manual upgrade.