There are very few programs out there that have a Windows Home Server compatible version, and BitDefender is one of those companies. Their current offering BitDefender Internet Security 2009 is compatible with Windows XP SP2 or higher/ Vists SP1 / WHS. It total secucrity package that locks out viruses, hackers & spam, while providing parental control and firewall protection.
The program is available as a free 30–day trialware from the BitDefender website. Prior to installing BitDefender, it is highly recommended that an on-line virus scan be performed at the web page illustrated below.
More info: BitDefender Internet Security 2009