Versions of .Net Framework:

                           Microsoft started development on the .NET Framework in the late 1990s originally under the name of Next Generation Windows Services (NGWS). The .Net Framework is first released in beta in November 2000 and development continues today. 

1) .NET Framework 1.0

2) .NET Framework 1.1 

3) .NET Framework 2.0

4) .NET Framework 3.0

5) .NET Framework 3.5

6) .NET Framework4.0