Is there anyway of downgrading a Visual Studio 2013 project to a Visual Studio 2008 project ? I need to run some C# programs created in VS 2013 with VS 2008.
See this answer. But I really wouldn't recommend this, even if it does work, which to be honest is not guaranteed.
Better to either create a new VS2008 solution and just Add Existing...manually bringing in all the source files, or better yet, just sign up for VS Team Services, grab VSExpress 2013, and you don't have to worry about conversion.