http://support.microsoft.com/ph/13029The latest support information about Forefront Security for SharePoint Solutions from Microsoft Product Support Services. http://technet.microsoft.com/en-us/library/bb795152.aspx#phrssSharePointThe bias setting controls how many engines are used to provide you with an acceptable probability that your system is protected (realizing that there is a trade-off between virtual certainty and system performance). The more engines you use, the greater the probability that all viruses will be caught. However, the more engines you use, the greater the impact on your system’s performance. While Forefront Security for SharePoint uses a very efficient in-memory scanning process, each additional engine adds to scanning time and resource usage. http://blogs.technet.com/b/fssnerds/archive/2008/11/14/required-accounts-and-permissions-for-installing-forefront-server-products.aspx#phrssSharePointExchange ServerManagement ConsoleThere are several different accounts and permissions that are required for successful installation of Forefront server products. This blog discusses those accounts and permissions.