I think you go into the control panel program in Windows 7, and search for Firewall in the top search box in the control panel window to diasable it, and then install your 3rd-party firewall program in Windows 7 by opening the installer file for your 3rd party firewall software.
I've been using Comodo since I was on XP. I used it as a replacement for the XP firewall and ZA. It is very good. As for replaceing the W7, that should be easy. You just install Comodo and it should automatically disable the W7 firewall, but if it doesn't, then you should be able to disable it on your own and if it gives you a warning then you can choose the option that says you have your own firewall and then install Comodo when it is disabled.
I use the free version, as for antivirus, I use Avira, which is also free. I dont use the Comodo DNS at all as it is as faulty as any other DNS service. I accidentally forgot to disable it once and I couldnt access my forum at all. It kept telling me that it either didn't exist or I mistyped the url.
No harm done or no hur[background=rgb(28, 28, 28)]t a[/background][background=rgb(28, 28, 28)]t all eh or oi[/background][background=rgb(28, 28, 28)]? I'd dare hope for ya![/background]
I tend to distrust DNS services because they look a lot like hijack pages.. and some fake DNS services as well the pages they take you to have viruses embedded in them.
I got a pm asking me about what a/v software I use but because I am using Tapatalk, I'm not sure if it went through or not. So here it is.