PC help: Is my PC a zombie?

Q I read with concern recent references in Computeractive to zombie PCs.

How can I tell if my PC is being remotely controlled and what can I do to protect it?

I have Norton Internet Security 2006 installed and I always disconnect from the internet when I have finished working online. Is this enough or should I install more protection?
Steve Chambers

A A general rule is that if you have working, up-to-date firewall, anti-virus and anti-spyware software installed, and your computer is behaving normally, there should be nothing to worry about.

Symptoms of being taken over include severe slowdowns, juddering windows or mouse pointers, lots of strange pop-ups or windows, and increased traffic on your router (if you use a router to connect to broadband).

Note, though, that having any of these doesn’t automatically mean you have a zombie PC – in fact, many of them are caused simply by malfunctions. However, if this happens, run a thorough virus and spyware check and contact your service provider to see if they have noticed unusual activity on your account.

In answer to your second question, it’s not necessary to install anything more, as long as all of Norton’s various parts are running, and fully up to date. You should not install another firewall or anti-virus program, as these will conflict with the existing ones.