Hi Barry, good advise but its free
For us too AV is essential in the corporate environment, We do stop the majority of threats with EMail scanning on our servers before emails are accessed by users on the network and our firewall will stop/spot any attempts to access pc's via ports but the biggest issue we have is laptops that are used outside the network and then connected to the network. We now encourage laptops to connect to the depot networks via the radio network which puts the user on a seperate subdomain to the main network
To give people an idea of the issue its estimated that only 1% of emails that are in transit at any one time are real, I know at work over 250,000 emails are stopped at our email scanner each day as being suspect or spam All very techy for the home user but browsing the internet should only need port 443 and port 80, port 110 and 25 is needed for email you can block all other ports on your firewall, If you use things like Skype and MSN then you will have to start opening ports on your computer, more ports open more places to be attacked. Therefore on our network we do not allow any of these types of program.If people are downloading and using cracked programs from Torrent sites, very often not only do you get the program you wanted but a couple of other programs hidden that you did not want. If you use Torrent sites then you must check everything you download, you may save a few pounds getting a free program but if you give away your bank account details at the same time???, a recent cracked copy of windows 7 that was around would pass all your IP address and login details to the guy that cracked it and the remote desktop connection was turned on by default
It is possible to survive without AV my home server has no antivirus as it slows machines down, don't open email attachments unless you were expecting them, Jokes are the worst for this. Don't go to websites that ask you to 'install' something before you can use the site
any AV software is better than none and some of the free ones are better than bad paid for ones. But its essential that you get updates every day. any AV is only as good as the last update.