Windows 7 Compatible Firewalls

Hey, I've recently purchased a new computer and it has Windows 7 on it. Recently, I was able to install one of the suggested antiviruses on it, however when I went to try and install the 3 suggested firewalls, I've gotten errors trying to install each one! I'm not sure if it's the fact that I have windows 7 running, or if it's something else I may have missed, but can anyone give me any pointers as to what I may be doing wrong?

I use Windows Security Essentials for my AV and the Windows 7 built in firewall. I don't see a need for anything else.

I did use the free Comodo Internet Security suite previously but find WSE much less intrusive and it does have good ratings as AV software.

Oh ok! I wasn't sure if it was absolutely needed to get a firewall running on this machine, since I've grown accustomed to using antivirus and firewalls that aren't from windows. Thanks for the input!

Well just incase you want a further option, the best result currently for this OS, or 64bit OS's, is to run the OS firewall and add Windows 7 Firewall Control to it, I like total control of what goes out, as well as in, windows by default lets everything out (as best I know), but adding this addition to the OS firewall gives you outgoing control again, pretty much like ZA does, the only annoyance is the stupid noise when a new item requests attention, funny to begin with, but annoying after the first few times, hope this helps a bit anyway.

Following from What's new in Windows 7 Firewall?

As with Vista, the basic settings for the Windows 7 firewall are accessed via the Control Panel applet. Unlike Vista, you can also access the advanced settings (including configuration of filtering for outbound connections) through the Control Panel instead of having to create an empty MMC and add a snap-in. Just click the Advanced Settings link in the left panel.

So I think my recommendation of Windows Security Essentials and the Windows 7 Firewall is good protection.