copied file has no file type

Hello can someone tell me how to add the file type to a file? I copied 2 video files from my samsung galaxy onto my dell PC but when I open properties beside file type it just says file instead of mp4 which I know they are because I made the videos. Im assuming the solution is fairly simple but I cant really find anything about it so here I am. Any help will be greatly apopreciated. Thanks in advance.,

Right-click one of them and Rename, type .mp4 then double-click and see if it opens.

Or open File Explorer, click View, click Options and on the View tab Uncheck the Hide extensions for known types, check the result, should show the file type if it has been assigned.

Berton said:

Right-click one of them and Rename, type.mp4 then double-click and see if it opens.

.mp4 is the file extension. You must put it at the end of your file's name like this: filename.mp4

It will help make things clearer if you turn on 'show file extensions', there's a tick-box for this in File Explorer's 'View' tab.