In Windows 8 when you try to install an old application then you have a problem and a message such as "An app on your PC needs the following Windows feature" ".Net Framework 3.5 (Includes 3.0 and 2.0)" is displayed and the application doesn't install. This type of problem exists because the application that you try to install requires a .Net Framework 3.5 feature. In Windows 8 .Net Framework 3.5 is disabled by default. When you install Windows 8, .Net Framework 3.5 is not installed automatically, only the .Net Framework 4.5 Advanced Features are installed automatically. If you want to enable .Net Framework 3.5 then you must manually install .Net 3.5 in Windows 8. There are two ways to install .Net Framework 3.5. The first is online and the second is offline.
This article will explain how to install .Net Feature 3.5 in Windows 8 offline. To install .Net Framework 3.5 offline you need a bootable media, such as a Windows 8 DVD, Windows 8 bootable pen drive etc.
How to install .Net Framework 3.5 in Windows 8 offline
Insert the bootable media in the computer and go to the search box and type "CMD" and from the results window open the command prompt as Administrator.
In the command prompt go to the root directory. Do that by typing "cd /" then hit Enter.
Now type the following command into the command prompt. Here "Source:F" is the bootable media, such as a Windows 8 CD drive, Bootable Pen drive etc. "Source:F" might be "Source:D" or "Source:E" depending on the name of the drive.
Dism /online /enable-feature /featurename:NetFx3 /All /Source:F:\sources\sxs /LimitAccess
After typing the command and pressing Enter, wait a while. After installing .Net 3.5 you will get this message:
Now restart your computer and try to install the old software.
To install .Net 3.5 online follow this link.