People are trying to help you, it's just a bit hard to understand what exactly you did to get mangos, and what you are using to build it.
Getting mangos should be a matter of using git to obtain the source code from github, opening your command line, and executing
$ git clone [url]http://github.com/mangos/mangos.git[/url]
You do however not need and vb (assuming you know this is the abbreviation for Visual Basic), you will need to use Visual C++ 2008 or 2010, and if you do not have those and only Visual Basic installed, it will result in a message telling you the project could not be loaded due to missing support.
That is exactly what people have told you, and people can not give more assistance unless you are willing to follow the given hints (which I repeated just for you in greater detail).