You only need the firewall from comodo and the av should be diabled during install, you cant have two av’s on the same system.
It is up to you and your skill level as to what firewall you wish to use, if your not very knowledgeable about all the program functions on the system i would stick with the windows firewall as its quite good in windows 7.
Being that you have had to ask this question i would recommend you to delet comodo, keep avast and add malwarebytes to your system.