Using CFP v3 I I sort of maintained having a up-to-date export of my main configuration. CFP v3 has 2 export options by default, one called "Optimum ..." and one called "Network ...". I always exported both, the "Optimum Security"being the one I use varying from initially 5MB to now over some 3MB and the "Network ..." exported listed always in size 180.224KB for me. Always exporting that one too as a sort of double check of not being used.
First install, running FP v3.0, I saw the "or visit
http://ww.comodointernetsecurity.com to download an upgrade application which will upgrade existing installation to COMODO Internet Security without loss of existing firewall configuration..." upon install, looked at the site and noticed it's some of can for the Comodo toolbar??? Nothing mentioned relating to the message from the installation?? Final version rite? Close the browser, relaunch the downloaded install.
So now:
1) export your main used CFP3 configuration (Miscellaneous>Manage My Configurations>Export>'marked Security option')
2) uninstall CFP
3) install CIS, upgrade solution used: no integrated AV (have a look at
http://av-test.org, if Comodo manages to integrate 2 known AV engines into their own I'd be glad use Comodo's AV -freeware isn't it- otherwise no thanks), no integrated Toolbar & other options, again no thanks
4) "Import" the configuration file from v3, either using "Import as..." or "Import..." and "Select" the configuration as the new active one; backup a new configuration file and delete unused configuration files.
/edit:
5) since CIS cannot be installed in for instance '..\Program Files\Comodo\Firewall' and has a '..\Comodo\Internet Security' path hardcoded in the installation options, verify the path from CIS files in the "Defense+">"Common Tasks">"My Protected Files" section because they likely contain the CFP path.
/edit
Defense+ from 3.5 already intercepting a larger load.