Disabled Add Reference in Solution Explorer on Visual Studio 2010

Question

I'm using Visual Studio 2010, and I want to add reference to make a project as said in this guide , but for some reason it is disabled.

Here is my printscreen picture, it explains it all.

Answer 1

You probably try to add reference when you debugging your code. Stop the debugging and you are free to add reference.

Answer 2

Make sure you are not in Debugging Mode . Add Reference option usually got disabled in debugging mode.