If you have tried using Windows 8, you must have noticed something else that for the program has to use Net Framework which will not run when you use the Net Framework current (new version), it will only work properly unless you install older version Net Framework. And obviously you can use both (old and new version) at the same time.

These ways below will show you how to install .Net Framework

Older versions of the .Net Framework have become optional extras in Windows 8, this means that if you want to run older programs you will need to enable them, to get started press the Windows + R keyboard combination then type appwiz.cpl in the run box before hitting enter.

When the Programs and Features section of Control Panel opens, click on the Turn Windows features on or off hyperlink in the left hand side pane.

Now you will need to check the box to install the .Net Framework 3.5.

The files will be downloaded from Windows Update and you will be prompted to reboot upon completion.

That’s all there is to it.

Via howtogeek.com