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I have a problem with Garmin 770 maps unlock - GPS Devices

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How to unlock this mapping to your Nuvi 700 series, if you get the error message “can’t unlock maps”
Please connect the Nuvi to the computer then follow the following steps:
1. Go to ‘My Computer’ and select your Nuvi.
2. Once you have selected the Nuvi go to the ‘Garmin’ folder.
3. Click options along the top toolbar of the open window, then select folder options.
Once the box appears, select the VIEW tab along the top and un-tick the ‘Hide extensions for known file types’, then click OK.

4. Once you are back in the Garmin window you will need to right click the window and
then choose NEW > Text Document:

5. Once you have the Text Document appear in the window you will need to name it:
gmapprom.unl (you may need to remove the .TXT extension).
6. Once the file has been created, right click on it and choose open. A window will pop
up asking you to choose the program to open the gmapprom.unl file, you will need to
choose NOTEPAD and make sure the box at the bottom that says to always use this
program for this file type is un-ticked and then click OK

7. You will then have an empty document open, in here you need to type your 25 character unlock code all in lowercase and without spaces or ‘-‘. After entering this,
save and close the document.
8. You can then unplug your unit and the mapping will be unlocked on the Nuvi. (Please note that if you have a Nuvi 770 then you will need to repeat this process again as you will have two unlock codes. You will need to name the second file

Posted on Jul 11, 2008

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they are very helpful garmin phone is

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