How to enable Net framework 3.5 after installing windows 8/7/8.1

First insert windows installtion Disc

Step 1 :
Open CMD.EXE with Administrative Privileges.

Step 2 :
Run the following command Dism.exe /online /enable-feature /featurename:NetFX3 /All /Source:G:\sources\sxs /LimitAccess, and hit Enter.

After completing the installation of .NET