A common question that appears in forums from time to time is how to guess the type of a project (Windows, Web Application, Web Site, Smart Device, Class Library, Console, etc.). The answer is not so simple and you have to check several properties. I have explained it in my this article:

HOWTO: Guess the type of a Visual Studio project from an add-in or macro
http://www.mztools.com/articles/2007/MZ014.htm