The sample programs and instructor solutions for the Advanced VB 2010 book are grouped into Solution folders. When you open the .sln file for each chapter in Visual Studio, you will see all the projects for a single chapter in the Solution Explorer window. Personally, I find this a convenient way to switch between projects without having to reload each one in Visual Studio. But if you prefer to open the projects one by one, you can just delete the .sln and .suo files in the root folder of the chapter. Then, you can go to each chapter folder and double-click the .vbproj file to open an individual project.