Unfortunately USB mass storage is not working on the Samsung Galaxy S3 and Galaxy Note 2, because it seems like Samsung disabled it somehow. There are only two USB file transfer modes available, the MTP ( media sharing ) and PTP ( camera mode ), which aren’t very useful for everyone.
But developers have found a workaround for the Galaxy S3, which also works on the Galaxy Note 2, but not so well. You will only be able to use the external SD card in USB mass storage and you also require root access. Once you make sure to have an external microSD card and root access, you will have to download a free app from Google Play.
So here’s exactly what you have to do in order to enable the USB mass storage:
Download SGS3 Easy UMS here. Then you will have to launch the app, grant it root access when you’re asked for it, and choose the way you want to mount your device on the PC. It’s very easy and you will only have to tap one button to switch from one mode to another.
Currently this only works with the international Galaxy Note 2 N7100 and the i317 AT&T version, so it’s not recommended to try it on another version. Though if you do, please let us know if it works or not, so we can update this article for other users.
Also if you have any questions or problems, let us know in the comments section and we will do our best to help you.