The easiest way is to upload your file to YouTube, then insert it as an online video. After uploading the video, use this official quick guide: https://support.office.com/en-us/article/Video-Insert-online-video-bf11b812-0243-4f53-a1f9-432fbf7ace2c
Insert online videos that you can watch right in Word without having to leave the document.
Click Insert > Online Video.
In the Insert Video window, you can search for videos on Bing or insert a video’s embed code. You also have the option to add other providers such as YouTube.
When you find the video you want, just click Insert.
If the Online Video button appears grayed out, make sure you’re not in Compatibility Mode. You know you’re in Compatibility Mode if [Compatibility Mode] appears after the document name in the title bar at the top of the Word window. To convert the document, click File > Info > Convert. To learn more about Compatibility Mode, see Use Word 2013 to open documents created in earlier versions of Word.
If you want to add videos from YouTube and you don’t see it as an option, click the YouTube button at the bottom of the Insert Video window. If you don’t see a YouTube icon, make sure you’re Signed in to Office 2013.
1Could you improve your question to include such information as to whether you have Internet access or if you have any other restrictions, as one of the answers describes a great solution (embed YouTube) but your question could prove difficult to answer as you are likely to receive a number of different answers that are all valid, but which is the best for your situation? – Kinnectus – 2015-12-04T11:19:05.230
please don't do this Word is meant to be used for Writing Documents/Letters that can be printed - how the hell would you print the information which is inside the Movie? - If you wanna do a Presentation there are better Tools like Powerpoint or Prezzi.com eg. - Also if it is a larger Movie think about what happens to your Word Document since the Movie is fully embeded your Word Document will be increased about the same size the Movie has so it will be a pain in the ass for other to open your Word Document if they have an older PC or havn't as much RAM as you have. – konqui – 2017-04-11T06:44:57.893