Find out how to remove Comodo's free firewall from their own site. There must be a removal tool. Win 7's own firewall is good enough. If Win 7 firewall burps an opinion not to allow, then click OK to not allow.
Avast, Malwarebytes, Superantispyware and Spywareblaster, all free versions is all you need if you manually scan. Avast is pro-active but not with the recent version of the program. Virus updates are.
Avast program updates are manual for the free version.