But currently it is not enabled in windows 8. So you have to do some extra work for it.
How to offline Enabling .Net framework 3.5.1 in Windows 8
To enable it you have to have windows 8 DVD only. Then insert it to your DVD drive. Restart your computer. You can ask me why i need to restart pc ? Yes because i was trying by inserting the DVD directly and run the cmd command but it never detect the DVD, but after changing the boot option and i restart pc after that it worked. Open cmd as admin then type this command below:
Just ensure the Windows 8 DVD is in the drive (or the ISO is mounted) and at a command prompt type:
dism.exe /online /enable-feature /featurename:NetFX3 /Source:x:\sources\sxs /limitaccess
Where X: is the DVD drive (or mounted ISO).
It will took few minutes to complete the process. After that you will see the successful message. Here i like to mention that don't use any program while doing this process. You must run cmd as admin. To complete this task you need to change boot option. Because while you restart your pc it will try to set up windows. So change the boot option while windows start to boot by selecting f2 for entering at bios and select USB CD ROM as first boot. Hard drive is 2nd and DVD ROM is third. Press F10 to change the Bios settings. Then you can restart pc to run windows 8. Okay now we will try to open cmd. To do that go to search write cmd click on app. Then cmd will open, right click on it and pin to task bar. Now from task bar right click on it open as admin.
The code is very important here. X is the drive letter of your DVD ROM. Just replace it with your own drive letter. Other would be same. No change need.
I hope following above method you can successfully enabled Microsoft netframework 3.5 in windows 8
Well, for more clear check this video below: