This guide is applicable to Windows users only.
Do you have video files, for example MVs and movies, downloaded or purchased from online websites that you want to add to iTunes on your PC? If yes, the following guide will show you how to do it.
Take note, as per the Apple Support website, videos that work on iTunes are QuickTime and MPEG-4 movie files that end in “.mov”, “.m4v”, or “.mp4” and are playable in QuickTime Player. 
Adding a Video to iTunes Library
1. Open the folder containing the video file you want to add to iTunes.
2. Right-click it, select ‘Open with’, then choose iTunes in the program list. See screenshot above.
The video will be played automatically and will be sorted under Home Videos. The program will auto-create that tab. It will not save a copy of the video in the iTunes directory unless you create a new version [File > Create New Version].
1. Open the folder containing the video you want to add to iTunes.
2. Open iTunes, then press CTRL + 2 on your keyboard to open Movies library.
3. Drag-and-drop the file from the folder to iTunes. If this is your first time doing this, the program will auto-create the Home Videos tab. Open it and you should see the video there. Double-click it to play.