Is this your desktop or laptop? If its the desktop it might be related to why your lego harry potter is not running.
Anyway, try turning the "Media Features" feature on and off. In windows 7 you can do this under Program and Features in the Turn Windows features on or off window. I hope Vista has something simlar to this.
If that still does not work, try searching MS if they provide some form of Media Centre component distributable which you can use to install / repair it. Searching the crash error message might reveal someone else in your situation and often gives nice solutions as well (like some systems may been a patch to run it properly).