<A target="_blank" href="http://www.theregister.co.uk/2009/05/08/win7_rootkit_poc/">As yet, it's a proof-of-concept</A> rootkit for Windows 7. Unfortunately, such concepts have a history of going wild soon after they're discussed. Vbootkit 2.0 can be stopped by the BitLocker harddrive encryption offered in Enterprise and Ultimate version of Win7.