[.NET 3.5 Offline Install]

put the win8 dvd in the drive

then write the line in text and make its name as cmd extention as wwed.cmd

then run it as administrator

Dism /online /Enable-feature /featurename:NetFx3 /source:G:\Sources\sxs

chnge the drive letter as in your pc here it is G write it in capital letter

[.NET 3.5 Offline Install]

edit it (change the drive letter in the cmd file as in your pc and put the win8 dvd inthd drive)

runit as administrator