just thought of another issue possibly.  Visual basic support for OS 7.0 requires
Visual Studio 2010 Professional or higher plus an additional download.  For OS 7.1 (Codenamed Mango) I believe VB support is fully included.

For Windows Phone 7, download links for everything are in:

http://channel9.msdn.com/Series/Windows-Phone-7-Development-for-Absolute-Beginners/Installing-Visual-Studio-2010-Express-for-Windows-Phone.  

Mango beta tooling:  http://www.microsoft.com/downloads/en/details.aspx?FamilyID=77586864-ab15-40e1-bc38-713a95a56a05&displaylang=en