Step 1:
Insert Windows 8 DVD or mount ISO image. The source of this feature can be found in folder E:\sources\sxs. (In this case E is the user’s drive letter on which the user has loaded Windows 8 Media.)
Step 2 :
Open command prompt with Administrative Privileges. Press Windows + X key then click on Command Prompt (admin). Click yes when it prompts for your permission .
Step 3:
Type the following " dism/online/enable feature /feature-name:NetFx3 /All /source:E\sources\sxs /LimitAccess" then hit the Enter button
Step 4:
Wait until it's 100% and you're done. :)
