Undo VS 'Exclude from project'?

visual-studio

Solution

Make sure you are showing all files. There is a button at the top of the Solution Explorer called "Show All Files". To see this button, make sure that your project is selected in the solution explorer.

Show All Files

When this option is active, the file should be there, just grayed out. Right click it, and select "Include In Project".

Include In Project

Problem

Is there a way to undo the 'exclude from project' operation in Visual Studio (2008) ? How to include files back into the project after excluding them?

Original source