The likely cause is that the version of Visual Studio you are using is not the same as the one I used to write the book code. Visual Studio can tell from the header info if the versions are not identical and you will always get the conversion message you mentioned. While I can't be sure, perhaps you are using the Standard or Professional version of VS but I used the C# Express version to write the book. I don't think you should have any problems with the converted code...VS seems to do a good job in making the conversion.
Jack Purdum, Ph.D.
Author: Beginning C# 3.0: Introduction to Object Oriented Programming (and 14 other programming texts)