I do not know of an issue like this with MediaLab on Vista, but then I am mostly aware of this via v2008 installations. If it were me, I might try 1. checking other samples, 2. checking that you have full user permissions on the C:\MediaLab folder, and 3. reinstalling. If none of those options produce a fix, then I would at least try installing v2008 to see if that makes the difference. Because, no, I suspect if you can not run Sample 1, Condition 1, then you will not be able to run other studies because that sample is about as simple as MediaLab gets.