You can just take a glance and have a try: If you have MP4 version at present and have to use some third-party tools (after my research, Microsoft has officially reclaimed that they do not support flash, so I think you can only use some file converters to try to create your customized screensaver.), why don't you just apply some third-party tools to convert MP4 directly to scr.? After my research, you can use iScreensaver to transform your file versions, as I know, they offer a version that can be downloaded for Windows 10 users.
