Yes, it can be mapped to a drive letter. It was a lot easier with something like Droid X (Android 2.3), as it displayed as a mass storage device (disconnecting the board from your phone in the meantime), but it is also possible on newer phones like LG G3, if you ready to install 2 free programs that you probably would like to have anyway.
ES Explorer - Remote Manager (FTP Server)
First, you need a file manager, not only because the built-in one is useless, but also because you need an FTP server. Install "ES File Explorer" on your Android device. Then, in the options, enable the "Remote Manager" option, which activates the FTP server and shows you its local address, for example, "192.168.1.3:3721". Now you can access your phone as an FTP site from your computer when the WiFi network is on your computer.

Net Drive - Remote Disk Mapping Utility
Further, all you have to do is install NetDrive: http://netdrive.net/ It is free and seems to be used by many companies because it allows you to map cloud storage to local drives. This will allow you to display your FTP server on your phone as a local drive.

Do not try to map the FTP site to Explorer. First, you may run into a problem that is apparently caused by Chrome, where you cannot even add an FTP network location. You will receive an unexpected error indicating that the format of the path is invalid. Interestingly, this is allowed by opening the registry editor, then in [HKEY_CLASSES_ROOT \ ftp] add a key named "ShellFolder" with the string value "{E436EBB6-524F-11CE-9F53-0020AF0BA770}". The error will stop immediately, without restarting or any other actions. Just go back and add the ftp network location. However, this still does not allow you to match it with the drive letter, so you need NetDrive.
Triynko
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