If the sole purpose of the this network is to access the web, why not set the individual PCs up as thin clients
connecting to your server? That way, you won't need to worry about the individual machines at all since AV and (everything else!) will be provided via the host machine.
Check out the Linux Terminal Server Project
) for more info:
The Linux Terminal Server Project adds thin-client support to Linux servers. LTSP is a flexible, cost effective solution that is empowering schools, businesses, and organizations all over the world to easily install and deploy desktop workstations. A growing number of Linux distributions include LTSP out-of-the-box. Edubuntu
can create an LTSP server for you if you do your installation from the alternate
rather than the live CD. Hit F4
after you select your language. Then from the Modes
menu select the LTSP option and it will walk you through it.
The Edubuntu folks have a nice 'cookbook' page for getting LTSP up and running under the Ubuntu family.
Might be worth a look.
Note: AFAIK the only
NIX AV software that allows for free commercial/business use is ClamAV
- which is not the greatest.
For Windows machines (including Server 2003!) you can use the latest version of MS Windows Defender
. It's getting good reviews. Independent preliminary tests indicate it provides acceptable levels of protection and compares favorably with some of the big names.