How to convert garmin express map data sets into a portable format


"How to create a portable map data set."

Practically this is easier done than said. I can do all of this in just a few minutes vs the 20 or so it took to type out each step. The benefit is a completely portable map data set with absolutely no reliance on basecamp or any of the other bloatware that gets installed with it. I can't recall where I got these batch files from originally, but it was many years ago. The method has continued to work. After the process is done I simply restore the VM to a previous state before any garmin software was installed.

In the VM

1) Download and unzip into a temp folder

2) Edit convert.bat to reflect path where you want

3) Copy the 4 files from the temp folder to the following folder;


The cryptic GUID (long series of numbers) might differ, but the rest of the path will be same, adjust accordingly.

4) Open an elevated command prompt (cmd run as adminstrator).

5) Change path to the above then execute convert.bat

This will convert the map into the old format. Takes about 20 seconds here, but will vary with system and hd speed.

6) Once converted, copy the entire contents of x:garmin to the host pc. Lets say to c:garmin

7) Also copy FROM the vm TO the some folder on the HOST contents of the following folder -
This contains your unlock code/keys to be used later


8) Back on the host, Mapsource should already be installed before proceeding.

9) Go back to the temp folder in #1 and edit convert.bat

Change the path to WHERE you copied the files to #6 above.

Save and then edit convert2.bat

REMOVE everything between and including

"echo This batch converts garmin gmp maps to img maps."


"echo Now this batch will install registry keys for CNE"

Save the file.

10) In an elevated command prompt, go back to the temp folder in #1 and run convert.bat. This will install the necessary registry keys so mapsource can find the mapdata.

11) Open mapsource. It will complain about locked map files. Click on Unlock maps.

12) Click on the Unlock Regions tab, then import.

13) Point it to where you copied the files in step #7, and select *.gma from the file type drop down box. Select the appropriate gma file then click open.


No comments?

No comments? smile

I don't know what problem you are solving

You've obviously worked hard at this but left something out. Perhaps others understand, but I don't know what problem you are solving.

I already run dual-boot with Ubuntu and Win10. I'm not likely to put up another operating system with it's overhead and more importantly it's learning curve. I don't know which VM you are discussing or if that even matters.

Main goal of this is to keep

Main goal of this is to keep garmin express away from the main OS. The virtual machine is a windows VM. Can be under virtualbox or similar. I use vm workstation.

I tend to be very picky of what gets installed in the main os. Everything else, or programs I use rarely goes into the virtual machine. Keeps things tidy and uncluttered.

I don't blame you for being picky

I don't blame you for being picky. I don't get worked up about Win10 since I use it for maps and maybe something else that I can't think of now. Not precious to me like Ubuntu is.