SBS 2008 ships with a trial version of Microsoft OneCare for Servers to provide a three months trial of the Microsoft anti-malware solution. However, the retirement of OneCare has just been announced and no replacement has yet been announced for it, so installing this product is just a stop gap until an alternative arrives.
To this end, I am simply going to say that you configure OneCare from the Windows SBS Console Home tab. From here, select Help protect your server with Windows Live OneCare for Server and the OneCare configuration screen appears. If you have not subscribed to the update service, it will prompt you to do so.
If you are not installing OneCare, then you must install another anti-malware solution. Personally, I do not like those that install alternative firewall solutions as I often turn these off due to the issues they create.
Looking at the OneCare settings, you can see the areas Microsoft recommends your anti...