title: How do I add my new User Control to the Toolbox or a new Winform?
body: <p>I have an existing library (not a Winforms application) that supplies some Winforms to a bona-fide Windows application.  Within this library, I would like to create a User Control to group some controls together.  To accomplish this, I <strong>right-clicked, Add, User Control</strong> and dragged some controls onto the new User Control.  </p>
  
  <p>So far, so good.  The User Control even has the requisite User Control icon.  But dragging the new User Control from the Solution Explorer to a new blank Winform does not work (I get a circle with a line through it), and dragging it over to the Toolbox doesn't work either (even though I get a + sign when I drag it over the Toolbox).</p>
  
  <p>Is there some sort of XML magic or something else I'm missing to make this work?</p>
  
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  <p><strong>Note:</strong> I had some problems with Visual Studio 2008 that I managed to fix by following the workarounds that can be found <a href="http://connect.microsoft.com/VisualStudio/feedback/details/363321/choose-items-in-toolbox-causes-visual-studio-2008-sp1-to-crash">here</a>.  I am now able to get User Controls I added to my existing project into the toolbox by simply rebuilding the project.</p>