You may want to know where the 4D folder is located on your machine, for example, to find the macro file used by the new method editor. As stated in previous technical tips, 4D is using a function from the system (SHGetFolderPath) to know where its preference files can be created. Unfortunately, there is no absolute way of knowing where that would be, since the function will return a path that depends on the operating system and, in some cases, your specific machine.
This path can be retrieved from the language by using the Get 4D folder command. You may also find the path to the 4D folder in the Program page of the "About 4th Dimension" dialog.