Copied Unreal Engine from friends PC but not working

I have downloaded Unreal Engine 4.19.1 version on my friend’s PC and installed it , Now its working perfectly on my friend’s PC but, Now, to have unreal engine on my own PC so ,I have copied all the folders and placed it in the same directory in my PC. But unreal engine launcher/ Epic game launcher is not going to load it is still displaying an install button in Epic Game Launcher is there any way to avoid the installation of Unreal Engine on many PCs if we have?

I’ve never copied the whole folder across, but there might be a “generate project files” batch file in the folders somewhere that might help the launcher recognise a new install directory.