This is a readme for DLL example: just follow that MSDN tutorial, generate dll first, then generate a main code referred to dll. Visual studios: 1. http://social.msdn.microsoft.com/Forums/en-US/Vsexpressvc/thread/d89f61e7-e354-4659-853c-d1faa65a4fc6/ unable to start a dll. 2. DLL:http://en.wikipedia.org/wiki/Dynamic-link_library http://msdn.microsoft.com/en-us/library/ms235636(v=vs.80).aspx great tutorial for DLL! Advantages of using DLL: http://msdn.microsoft.com/en-us/library/dtba4t8b(v=vs.80).aspx