For Windows 10 (as administrator or have your admin password ready)
If it doesn't run, couple of things to check.
1.) Make sure security software is in sleep mode & anything like "auto protect" is off. (Or just put launcher on your white list.) Some aggressive security programs will auto-delete the launcher based on "community reputation" etc. File might 'appear' as being there, but file size = zero? : 0 !
2.) Download launcher again if necessary.
Right click "Enderal Launcher.exe" & select "Properties."
Select "Compatibility" tab & click on "Run compatibility troubleshooter" (recommended) - will test it & go with what Windows thinks is best.
You can also enable check box "Run this program in compatibility mode" & access a pull down menu -- goes from windows 8 to Vista
Not much but hope it helps!