IDE Support (for Visual Studio 2005/C# 2005 Express):

Project LINQ relies on several changes to the C# language.  C# 3.0 contains new keywords and syntax that are not considered valid by the Visual Studio 2005 IDE.  The result is that editing LINQ-enabled C# code can be difficult: For example, there is no IntelliSense™ support for the new language features, errors are incorrectly reported in the output window, and the code editor underlines valid C# 3.0 code with red squiggles.  A modified C# language service has been created to help alleviate these problems in the IDE, to provide the new keywords in the completion list, and to provide extension methods in IntelliSense™.

While this preliminary IDE support greatly enhances the editing experience when writing C# 3.0 code in VS 2005, the language service and compiler are still very much in an alpha phase.  In the event of a compiler error, many more errors may be reported than are actually present.  If you see a large number of errors when building C# 3.0 code, fix the top error in the error list first and build after each fix.

Follow these steps to enable LINQ IDE support for Visual Studio 2005 and Visual C# 2005 Express: 

1. First, verify that you are running the release version of Visual Studio 2005 or Visual C# 2005 Express.  The language service that will be installed only works with the English version of VS 2005/C# 2005 Express and may cause severe problems if installed on earlier versions.  You can verify your version by selecting Help\About in Visual Studio 2005. 
2. Shut down any running instances of Visual Studio.
3. Open the \bin folder under the LINQ preview installation directory and run “Install C# IDE Support”.
4. Start VS 2005/C# 2005 Express.

Follow these steps to restore your original VS 2005/C# 2005 Express language service:

1. Shut down any running instances of Visual Studio.
2. Open the \bin folder under the LINQ preview installation directory and run “Uninstall C# IDE Support”.
3. Start VS 2005/C# 2005 Express.