Danger Will Robinson (Fun with Hyper-V)
In the process of installing Hyper-V for a customer, I made two discoveries. The first discovery was that the only way to manage Hyper-V on a Server 2008 Core system is from another, remote 2008 system or a remote Vista SP1 box. In both cases the Hyper-V Management Tool (MMC) must be installed separately. For Vista SP1, it's a free download. For Server 2008, it can be installed via the Features. This would of course pose an issue in an XP only environment with a single Server 2008 system. Of course, the customer that I at was XP only; luckily, they did have another Server 2008 system.
Now for the second discovery: instead of installing the Hyper-V tools from features, I installed the Hyper-V role because I didn't know about the feature. Not a big deal, everything installed fine, rebooted, and everything was still fine. Then I discovered that I could just install the tools via Features so I decided to remove the Hyper-V role. Again, not a big deal. Wrong. In the process of starting up (yes, a reboot was required), the server hung at Installing Updates – 75% for 20+ minutes. Uh-oh. I could connect to the server remotely and look at the logs, but there was nothing significant or out of the ordinary in them. Time to turn to my trusty web search tool of choice and bam: http://support.microsoft.com/default.aspx/kb/950792. Not sure who to blame this one on, but at least I wasn't the first to experience it.