[OTGamer]

Check the file permissions of the "Program Files" directory and make sure those permissions are full under the account you are running.

My experience is with XP. I've noticed even Admin accounts sometimes wind up with less than full access to the "Program Files" directory. If I run WPP on an Admin account that does not have full "Program Files" privileges, it will terminate when I try to begin a scenario. If I give the account full privileges (I have to do this explicitly for the Program Files folder), all is well. Perhaps something similar is going on with Vista? This is just a possible solution; it is probably something else. But it won't hurt to check to be sure.

And while you're at it, make sure the KE Studios folder has full privileges as well.