At least one reader has noted that there is an extra file in the Databases.zip file which is part of the downloadable source for Microsoft ADO.NET Entity Framework Step by Step. The Rewards2 RowVersion.mdf file isn’t used by any of the examples in the book. This was a test file that I used for experimentation purposes and you can safely delete it or simply ignore it. You certainly don’t need to install it in SQL Server. I had actually forgotten about that file and uploaded it with the rest of the downloadable source. I’m sorry about any confusion that the extra file has caused. Please let me know if you have any questions about it at John@JohnMuellerBooks.com.