I am running a new instillation of Windows 7 on my personal computer and would like some advice/recommendations on free anti-virus and firewall programs for a system where users will be engaging in risky activities. (Downloading of potentially unsafe files and navigation to websites where said files are acquired.)
Free Anti-Virus and Firewall Solution
If you're not happy with Windows Defender and Windows Firewall, there are a plethora of other free tools at your disposal. In my personal experience, the best source to find the latest scores of an application (Anti-Virus in this case) would be: AV-Comparatives.
Whilst there is no "end-all-be-all", I would recommend Comodo Internet Security (There is also Comodo Cloud Anti-Virus, I have no knowledge of this product). Whilst I will not go into details (nor do I have any real answers on how effective this is), you can look at the feature tab for the anti-virus engine.
Lastly, to finalize the "suite" there is also a "secure" line of browsers: Dragon Internet Browser, Comodo Ice-Dragon and Chromodo. There are all spin-offs of current browsers (Chrome, Firefox and Chromium) with Comodo's inbuild "SecureDNS" and other add-ons.
None of these, of course, will mitigate all possible issues when downloading files that, quite frequently, have malicious code. What you're asking for is more how to minimize the threats. For this, I could recommend the following add-ons for a web browser also:
- AdBlock Plus
- Disconnect Safe Search
- HTTPS Everywhere
- Web of Trust
- Click & Clean
- View Thru
- KB SSL Enforcer
(Note none of these will directly improve security, a conscious effort from yourself to browser safer is still required - and these work for Google Chrome).
As for all your questions on Browser Security etc. this belongs on Super User.