If you have installed the Windows Identity Foundation (WIF) SDK, and yet the Add STS reference option is not showing when you right-click a project in your Visual Studio 2010 solution, it may be because you installed the SDK when logged in as one user, but are attempting to use it when logged in as another. It is a known issue of the SDK installer that it only makes the addin available to the installing user. If that might be the cause of your problem, follow these steps to make the addin available to your current user.
- Close all instances of Visual Studio 2010.
- In a DOS prompt, enter the command CD "%USERPROFILE%\Documents\Visual Studio 2010"
- Now that you're in your Visual Studio 2010 directory, enter the command MD Addins. This will ensure that you have an Addins directory.
- Navigate to the Addins directory with CD Addins
- Copy the addin to the new directory with COPY "C:\Program Files (x86)\Windows Identity Foundation SDK\v4.0\Visual Studio Extensions\Microsoft.IdentityModel.Tools.VS.VSAddin.Addin". (If you are on a 32-bit system, the SDK will be in "Program Files" not "Program Files (x86)".)
- Restart Visual Studio 2010.
- Open a solution.
- Right-click on a project. The Add STS reference menu item should be available on the menu.