title: Best .net framework version to work with Windows xp,7,8 without installing or updating it separately
body: <p>I am going deploy a Windows Form application developed in C# using Visual Studio 2012. I do not want the user to download or update .net framework version. So what is the best .net framework version that most of the windows versions come with pre-installed and enabled ?
  (Preferably Windows xp,7,8)</p>