When installing CIS, you get an option of having Comodo DNS. (Which is a good thing). How about putting an option to revert to using the DNS you were using before in case you can’t use it
I had that problem, when I started using “AT&T Mobile connection” to get to the internet. I had to switch from the COMODO DNS back to my old one 
. I didn’t recall what my old DNS was, so I had to do some quick research using someone elses machine. Even still, it didn’t work right. I put Comodo firewall and defense + in training mode then restarted the computer and got online. Then I took it off of training mode and back to normal. <----That fixed everything
Just an idea 
Hi Jay. +1 for your idea, I didn’t know if this little program could fill the gap until something like your suggesting does get added to Comodo programs that use secure DNS. I have not tried it myself as yet.
Kind regards.
I didn't know if this little program could fill the gap
If I'm going to jump something, I'd jump the hardware mac address :o If you can't play with the firmware, then what good is that LOL...... :) But on a serious note :-La
Another reason for suggesting it is because when comodo switches the dns to comodo’s dns, it should remember the old one, that way if it needs to be changed back it can be done. (Also 99% + including me never bothered to write the old dns down on paper or in a text file before switching over