title: how to add System.Windows.Forms in visual studio 2010
body: <p>i used visual studio 2010 and i need to add System.Windows.Forms in my project but when i am trying to add this then it shows error i.e.</p>
  
  <p><img src="https://i.stack.imgur.com/uoYXn.png" alt="enter image description here"></p>
  
  <p>please give me solution for this</p>