Garmin Nüvi connected as media device - disable MTP, enable mass storage

What is MTP mode and which automotive devices use it?

Some automotive devices use Media Transfer Protocol (MTP) for connecting to your computer. MTP provides a more secure environment for the important system files on your device.

MTP connectivity requires the following:

• Windows XP with service pack 3 or later
• Windows Media Player 11 or later

The following devices use MTP  mode:

• dezl 760
• nuvi 2405 series
• nuvi 2407 series
• nuvi 2408 series
• nuvi 2505 series
• nuvi 2507 series
• nuvi 2508 series
• nuvi 2707 series
• nuvi 2708 series
• nuvi 3400 series
• nuvi 3500 series
• nuvi 3507 series
• nuvi 3508 series
• RV 760
• zumo 350

If the above system requirements are not met, or you are using the device on a Mac, the device will connect to the computer using standard mass storage mode instead of MTP mode.

[source]

Make NUVI DIR & Files visible for Backup

1. To make all of Nuvi files visible you must unhide protected files via Win7 like any other HD.
2. Start NUVI by itself and go to Volume Screen.
3. Press the upper right hand corner of screen for 10 seconds.
4. The Developers Screen will pop up
5. Scroll down to MTP SETTINGS
6. Change from AUTO DETECT to MASS STORAGE
7. Shut down NUVI and hookup to Computer USB cable
8. Start NUVI and it should recognize it is hooked up to the computer.
9. Explorer will now see all files in ROOT directory and the .System directories.

BTW, have you backed up your Nuvi? If not, then this would be a good time to do it. Could save a lot of grief later if you have a problem.

[source]