I have installed Visual Studio 2012 Professional on my machine. I don\'t have Visual Studio 2010 installed, but I want to keep developing my applications using .NET Framewor
You fixed your problem, but it's likely that .NET Framework 4 Targeting Pack (not to be confused with the .NET Framework itself) failed to install for some reason. Did you get a warning at the end of the Visual Studio installation? Either way, in the future, a repair install of Visual Studio 2012 should have fixed the problem (Add or Remove Programs -> Microsoft Visual Studio [Edition] 2012 -> Change -> Repair).