Windows Movie Maker is and always was a free program which is part of Windows Essentials.
Good that you didn't use the links which were supplied by another user and which will be soon deleted by an Abuse Moderator.
Although Windows Essentials is not supported (won't get any updates) anymore, you still can download the offline installer. During the installation you can choose which programs you want to install.
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Windows Essentials latest version 16.4.3528.0331:
English (United Kingdom)
English (United States)
English (United Kingdom)
http://web.archive.org/web/20121005063027/http:/g.live.com/1rewlive5-all/en-gb/wlsetup-all.exe
English (United States)
http://web.archive.org/web/20120811092624/http:/g.live.com/1rewlive5-all/en/wlsetup-all.exe
Other languages are listed here: https://answers.microsoft.com/en-us/windowslive/forum/moviemaker-wlinstall/what-to-do-before-movie-maker-goes-away-jan-10/8b3a5345-7840-4a2c-922a-cf24d10771f7?page=2&msgId=7fbd8015-d7af-44ed-b81d-0d73e8abac45
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Some other free video editing programs are listed here: https://www.provideocoalition.com/free-video-editing-software-2017-guide/
Hope this helps.
*much later EDIT