Recently, I tried to make a battery app (C#, store app) for Windows 8.1 (I am using VS2013, tried also VS2012 with the same result). As it turned out, I need to add a Reference to the project - but I cannot add anything in Reference Manager: it says "All of the Framework assemblies are already referenced". And all what I need is to get System.Windows.Forms - when I search for it, nothing appears.
Any ideas, what can I do? (Please tell me if I forgot something essential)