Comodo will not install b/c it's incompatible with Comodo Internet Security 4.X?

The Comodo Firewall which I have been using for the last 18 months all of a sudden stopped working last night. It might be because I just installed and updated my Avast antivirus program. Now I am trying to install my new Comodo CFWFree program but it won’t proceed because it’s incompatible with Comodo Internet Security 4.X. How can Comodo be incompatible with…itself?

I tried to get rid of all Comodo traces with a Revo installer on moderate setting but I still keep getting the same message. Help please. ???

Vista 64 bit
Avast anti-virus

Hello Udo. I’m sorry but I do not fully understand your query, Lets try to work this out.

You had Comodo installed and then you installed Avast, the next day Comodo wouldn’t work. You uninstaller it using REVO and then tried to install comodo again without success. Is that right?

What previous version of comodo did you have installed? what version are you trying to install now?

I am trying to install “cfwfree_installer_x64” directly from the Comodo website so it must be the latest version. I don’t know what version of Comodo I was using up until yesterday but it worked fine for 18 months on my laptop.

basically you have leftovers, I would say in the registry. did you do a restart after running revo? Also try running this batch file to remove leftovers then do a restart and try installing again.

I did not restart after deleting through Revo. I will try that first. Thanks.

In fact Windows needs two reboots to clean all the drivers.