[ddouglass]

Do a Google search for Wave Editors and find one that is free. They all set the right registry keys. Install it and this will hopefully fix the problem. That is the solution that has worked for most. The reason for the error is Vista and Xp do not have the correct settings for WAV files. Medai Player should have taken care of this but for some reason doesn't.

If you have any Microstudio folders in the C:\Program Files\Micro Technology Unlimited\Microstudio or C:\Program Files\Micro Technology Unlimited\Microstudio\Manual then they need to be moved to C:\MTU\Microstudio.
Also if you have any Microstudio files/folders in C:\Documents and Settings\(User Name)\Local Settings\Application Data\MTU\Microstudio they need to be moved to C:\MTU\Microstudio as well.

Microstudio does work for the majority of the users both on Vista and XP otherwise MTU would have pulled it back and tried to fix it. Version 4.006 has been out for quite a while now. Just because you have a problem does not mean the version is not working for others. I understand your frustration but it doesn't help to get the problem solved.

When you say your Vista is "fully up to date does this mean you have been to Microsoft's Update web page and installed all the "Custom" updates or that you have the Auto update turned on and updating your computer? If it is the latter then that does not get all the updates necessary.

What version of Microstudio did you upgrade from?