Maybe to go to a wizardBut a very good one. He can guess what device it is and how to help.
It is not a problem.
The thing is, every navigation device and its software come with so called "launcher". It's part of the system, usually simply done, from which you call with a few shortcuts of the main function and navigation software.
Your device is most likely "unlocked" and runs WinCE directly.
If you want to restore standard functionality, you need an original firmware.
Find it based on the exact designation of the model and the manufacturer.
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