This data directory is used by several of the other LINQ samples. Note the copy of the database entitled Northwind.mdf found in this directory. This is a custom version of Northwind database that is used by many Microsoft products. Changes made to this database include the addition of new stored procedures and fields designed to show off particular LINQ features. There is a second copy of this database in the SampleQueries project. Two copies of Northwind were shipped so that SampleQueries can be copied easily as a discrete entity from one location to another. If you move other samples, such as LinqToNorthwind, you would also have to bring this Data directory along with it.
Other files found in this directory include various small XML files that are used by some of the other LINQ samples. Note that these XML files are again duplicated in the SampleQueries directory, for the same reason outlined above.
It is important that the files in this directory are not marked as read only. Many of the samples will not run correctly if these files have their read only attribute set. In particular, you may have trouble connecting to the Northwind database unless you have permissions to both read and write to Northwind.mdf.
The following text, which summarizes some of the information explained in this file, is duplicated in most of the other ReadMe.html files included with the LINQ samples:
Many of the LINQ samples require XML files and/or the version of the Northwind sample database that is located in the Data sample. If you install the Data sample under the same parent folder as the other LINQ samples, then the path for the XML files and database file will be resolved automatically. Many of the sample files also require the ObjectDumper project.