Have you tried Miscellaneous/Diagnostics this works for some people.
Dennis
EDIT It is Defence+ and not the firewall/network?
Are you installing it on non standard drive (other than C:\)
Did you completely remove CPF3 before you install again.
I removed it in safe mode using Windows Add/Remove programs. Restarted when it said to. Once Windows loaded and logged on I stopped the Windows Defender services via the Administrative services. Checked that the program (Comodo) from the Start Menu was no longer in Programs and proceeded with the re-install to C:\. This is an old computer so things are real slow. Even though it has 320MB Ram. During the installation process it supposedly checked for malware...it seem to have finished as the screen goes black then a few seconds later a window comes up saying installation is complete. I then open the firewall to find the same status alert. So did I remove the firewall? I guess so.
I dont know or have Miscellaneous/Diagnostics tools that would check the problem with this issue.
The error seems to be with Defense+ status. If you like I could get a screen capture of it. It gives warnings whenever I do anything from opening the browser to opening add/remove programs. It warns about everything. So I think the firewall portion is working.