Best .net framework version to work with Windows xp,7,8 without installing or updating it separately

Question

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)

Answer 1

The most commonly installed .Net version is .Net 2, However WinXP does not have a default .Net framework installed

From Wikipedia: http://en.wikipedia.org/wiki/.NET_Framework

.NET Framework 1.1: Windows Server 2003
.NET Framework 2.0: Windows Server 2003 R2
.NET Framework 3.0: Windows Vista, Windows Server 2008
.NET Framework 3.5: Windows 7, Windows Server 2008 R2
.NET Framework 4.0: n/a
.NET Framework 4.5: Windows 8, Windows Server 2012

Answer 2

You cannot assume that any version of the .NET Framework is installed. Windows is not a .NET Framework delivery channel.

It is absolutely imperative that you have a plan to install the version of the framework on the computer if it is not already installed. Generally, this is handled by an installer program, but you can also use ClickOnce deployment if you prefer.

The general strategy is just to choose the highest version of the framework that supports the operating systems you need to support and go with that one. Install it when it is not already installed.