http://blogs.technet.com/shawnt/archive/2008/07/25/issues-uninstalling-vm-additions-going-from-virtual-pc-2007-to-hyper-v.aspxA colleague of mine, Chris Avis, had a great post on his blog recently. It's exactly the kind of post I love, since it only takes a minute to read, but it has the potential to eliminate hours of excruciating troubleshooting. Here's the link . The problem:en-USCommunityServer 2.1 SP1 (Build: 61025.2)