Registry key under HKLM\SOFTWARE\EpicGames\Unreal Engine
Registry key under HKCU\SOFTWARE\Epic Games\Unreal Engine\Builds
After installing 5.2 Engine in a non-default location I noticed that it doesn’t show up in any of the above locations. However, launcher is still aware of it being installed, hence it must store this information somewhere. Where?
I had a similar issue - I’ve been writing some build scripts and needed to know which versions were installed and where. After a lot of digging around here and a little help from Microsoft’s SysInternal tools (specifically ProcMon: Process Monitor - Sysinternals | Microsoft Learn) I discovered that the launcher reads a LauncherInstalled.dat file located in the windows c:\ProgramData folder.
The ProgramData folder is held in the %ALLUSERSPROFILE% environment variable. The path to the file is %ALLUSERSPROFILE%\Epic\UnrealEngineLauncher\LauncherInstalled.dat. The contents of the file is just JSON structured text e.g.