Well Microsoft did it again. Another somehow well buried feature that really helps you sometimes.
It's about a self-diagnose of the Vista OS, where major issues with impacts on performance or starting/shutdown times will be nicely shown.
It's in Control Panel (classic) -> Performance Information and Tools -> Advanced tools. Of course you should be an admin.
You can see there what programs are hanging on shutdown or standby, what features have a huge impact on performance and so on. It even gives you links to solves some of the problems. And yes it works and no, my Vista box wasn't own3d by somebody that wants to put Microsoft in a neat light. It is a feature. Well hidden but it's still a feature.