Since Windows 10 is not officially released yet I suspect you’ll run into a number of things that don’t support it fully. If Microsoft Fixit utility does not run on Windows 10 then you might have some luck with a manual registry editing approach as described in comments of last link I sent: iTunes Uninstall Link. In your case you would probably search registry for EpicGamesLauncher. This approach is complicated because you would have to cross reference and discover many cryptically named registry entries from info you find. I discussed this in answer to this thread but your registry values might not be same so I wouldn’t be able to help you beyond this point since I’m not able to test on Windows 10 at moment: