Download .NET Framework 4.5 for Desktop, Server and Development Free Download

NET for Windows Store apps
Windows Store apps are designed for specific form factors and leverage the power of the Windows operating system. A subset of the .NET Framework 4.5 is available for building Windows Store apps for Windows by using C# or Visual Basic. This subset is called .NET for Windows Store apps and is discussed in an overview in the Windows Dev Center.

Portable Class Libraries
The Portable Class Library project in Visual Studio 2012 enables you to write and build managed assemblies that work on multiple .NET Framework platforms. Using a Portable Class Library project, you choose the platforms (such as Windows Phone and .NET for Windows Store apps) to target. The available types and members in your project are automatically restricted to the common types and members across these platforms.
For more information, see Cross-Platform Development with the .NET Framework.

Version 4.5

Version 3.1