Hey, long time ago i couldn’t uninstall Epic Games Launcher or launch it, or install it, or repair it.
So i tried to uninstall in the register with keys, but idk what i did.
So the issue was and is still " Specified user is not existing"
( Check the attachments)
Thanks for helping me 
127541-
Do you have any special characters in your user name? When you say you uninstalled with registry keys what exactly did you do in the registry?
Something you should check is the user appdata folders for any stored files that may be causing the install to stumble on from your previous attempt.
Have you checked that you have all of the prerequisites installed? (VS redistributables, etc.)
Hey Daamshadow-
I’m sorry that you are having an issue with the Epic Games Launcher. In order for us to offer the best support, we have recently modified the process for how Epic Games can help troubleshoot your Launcher issue. Please visit http://help.epicgames.com/ for technical support, here you can find information and solutions for common issues, as well as a contact form if you still need additional assistance.
Cheers