free commercial-use Antivirus solution (Win2003,XP,Vista)

[retroborg]

Hello,
I work in a small corporation / Enterprise and I have been searching for a free commercial-use Antivirus solution that includes an on-access real-time scanner (Hard Drive & Internet), e-mail (Outlook) scanning support as well as being able to update it via the Internet.

I have a Network domain that consists of one (1) Windows 2003 Server Standard Edition R2 (Domain Controller/ DNS/ DHCP / File Server) and thirteen (13) Client PCs using Windows XP PRO & Windows Vista 32-Bit Business. So I would need the Antivirus to fully support these operating systems.

So far, the only free for commercial-use (supposedly) Anitivirus solutions that I’ve been able to track down are the following, but I have no idea whether they will be able to fully cover the above said tasks?
Has anybody else here tried them and if so, how well do they perform?

Comodo AntiVirus Beta 2.0
http://antivirus.comodo.com/faq.html
http://antivirus.comodo.com/features.html

PC Tools AntiVirus Free Edition 4.0 - New Version
http://www.pctools.com/free-antivirus/
http://www.pctools.com/info/eula/product/anti-virus/
http://www.pctools.com/forum/archive/index.php/f-10.html

BitDefender
http://www.bitdefender.com/site/Downloads/browseEvaluationVersion/2/

Any help or suggestions on these Antivirus programs (Or any other that I’m not aware of) will be highly appreciated.
Thanks in advance.

[Nelson37]

Never seen Comodo, not impressed with PCTools, BitDefender OK but not high on my list.

Free solutions for Servers just not something I'm real big on. If possible isolate Server form Internet and scan from client PC's.

Norton products were good in the past but I no longer recommend their use, am fequently removing them for performance issues and occassionally complete loss of usability.

Frankly, you have a significant investment to defend. Would recommend spending some cash to do so.

AVG, Avast, Spybot S&D all excellent and inexpensive or free. A hell-raising, fire and brimstone, no-porn-or-you're-out-the-door speech and written policy manual are an absolute must. You don't go mud-running in the company truck, or park it in an alley in downtown New York city overnite, risking company property through negligence is unacceptable.

Setting up the router to allow only approved websites and removal of admin authority from all users eliminates much problem areas. Pay particular attention to any areas where unsupervised males have access, shop areas for mechanical types are a big risk factor.