Now install dot net framework 3.5 for your PC being offline.

Generally, we install .net framework 3.5 being online but now you can install it being offline. First insert the windows 8 CD on your PC then go to start menu and right click on Command Prompt (Admin)

 

 

Now copy the code shown below and paste on cmd 

dism.exe /online /enable-feature /featurename:NetFx3 /All /Source:F:\sources\sxs /LimitAccess

It will take 10-15 mins to install 

 

 

Be careful that here the DVD drive is /Source:F:. If you source is K then give /Source:K: