here's the deal. If you are going to have this machine on the internet - then you MUST install anti-virus, firewall etc.
That said - these programs run in the background and they can interfere with yourr NLE. One of the options is to manually shut these down before each editing session. Another (which I prefer) is to set up different user accounts. When you log in as "Editing" the machine does not load up any extra utilities or programs.
When you log in for "wedb" it loads up all the appropriate software.
Tip: Use FireFox as your browser. It is not as suseptable to security issues and browser hijack attacks.