Malware Removal Starter Kit

Many small- and medium-sized organizations use antivirus software, and yet new viruses, worms, and other forms of malicious software (malware) continue to infect large numbers of computers in these organizations. Malware proliferates at alarming speed and in many different ways, which makes it particularly widespread today.
This guide is intended for IT Generalists who want information and recommendations that they can use to effectively address and limit malware that infects computers in small- and medium-sized organizations. This guidance provides a set of tasks that licensed Windows® users can perform at no cost to create the Malware Removal Starter Kit. Recommendations for free malware-scanning tools are included. You can use these tools in combination with the kit to conduct scans, detect problems, and remove malware from your computer

http://www.microsoft.com/technet/security/guidance/disasterrecovery/malware/default.mspx#EHD