Network Access Protection (NAP) is a policy enforcement platform built into Microsoft Windows Vista and Windows Server 2008 (now in beta testing) that allows you to better protect your private network by enforcing compliance with computer health requirements. For example, a firewall must be installed and enabled and the latest operating system updates must be installed. With NAP, you can create customized health requirement policies to validate computer health before allowing network access or communication, automatically update compliant computers to ensure ongoing compliance, and optionally confine noncompliant computers to a restricted network until they become compliant.
“Back in March we had deployed NAP to ~30k clients internally at Microsoft. Since then we have been busy adding new domains and scenarios into our NAP deployment and our total reach has grown significantly. We now have over 120k clients reporting in on our IPsec NAP deployment. This includes clients reporting in from across the globe including Europe, Africa, Far East, South America, North America, and many other remote locations. … “
NAP Site: http://www.microsoft.com/nap
More information at source.