Installing Multiple Versions of the .NET Framework
Updated: January 2011
You can install and run multiple versions of the .NET Framework on a computer. You can install the versions in any order. To see which versions are installed, view the %WINDIR%\Microsoft.NET\Framework directory. (You should also view the Framework64 directory on a 64-bit computer, which can have 32 or 64-bit versions installed.) Each version of the .NET Framework has a directory, and the first two digits of the directory name identify the .NET Framework version; for example: v1.1.4322 for the .NET Framework 1.1, v2.0.50727 for the .NET Framework 2.0, v3.5 for the .NET Framework 3.5, and so on.
You can also redistribute the .NET Framework with your application. For more information on including the .NET Framework with your application, see Redistributing the .NET Framework.