What are some of the security measures that you use to protect your computer?

I was very surprised to hear on the news that more than half of U.K. businesses reported receiving computer viruses

Initially I started off with Norton's Antivirus when I first bought my computer

As time's gone on, and we hear of malicious viruses, trojans, keylogging and all the rest, I guess I've got a bit more paranoid about proper security

Gaining knowledge by reading what others have used for protection, I've added different software to try to keep one step ahead. Some I kept, some I uninstalled after trying them

So, now I have, apart from Norton, these others:

Ad Aware
Zone Alarm

Both can be downloaded for free

Let us know what are some of the security measures that you use to protect your computer?

Some other sites worth having a look at are -

1. Distributed Intrusion Detection System - See if your computer is part of a DOS attack

http://www.dshield.org/

2. Shields Up - Probe your ports and see how "stealth" your computer is

https://grc.com/ <-- Excellent Site