I have Mio C520 device. Can I put in it new Tomtom navcore and latest maps?
I have tried few times before, but I failed.

Does your MIO use a window based operating system like Win CE or WM ?

im sure it use CE but depending on the device its a cut down version of CE with quite a bit of the program missing , just had this with a nav man and its not as easy as just installing the navcore (which has to be 7.910) if its using CE5.0, more info on the device would be good, got some great help of the navman forum and think i understand enough to help out

For Mio device you can find good unlock solutions like MIOPOCKET.
I would recommend Igo Primo or Garmin but not TT as IMHO the software is outdated and a lot of the features of other softwares are missing.

It is using windows CE Core 5.0.

right here goes i did this using the basic mio unlock desktop on a navman s50 running CE5.0 s so i would hope the basics will be the same.it may work
First unlock the device using miomoo unlock
On the storage card create a folder called Navigator and into that folder put theses files

[Please Register or Login to download file]

Now using your pc , look in the device root memory and in Programs you should find “FileManCE” move this into Desktop folder of the device and Reboot.You can now use FileManCE to run programmes on the desk top
copy your map ,voices, and fast activation tool to the root of the storage card
now using the file manCE on your desktop got into there and run the tom tom navigator .exe file it should be in Navigator\TomTom Navigator\tom tom navigator.exe .Run it until you get invalid maps
then on your pc go into the storage card and run the fast activation to patch device/ maps/ voices etc etc
that should have it working, too create a desktop shortcut for tom tom follow the 2 links below
[Please Register or Login to download file]
[Please Register or Login to download file]

also there is a bug in this navigator when you contect to car for use so, once you have it all running ,shortcuts created and maps patched .Then you need to overwrite the tom tom .exe file with a new one here in the zip for you. just rename the file by adding .exe on the end and copy it into Navigato\TomTom Navigator file and overwrite

hope this is clear enough
Be aware this is just a basic tom tom navigator program for mobiles etc so while you can have upto date maps and speed cams etc , you will not be able to use tt vocalizer for street names or ALG

also added is the miomove desktop unlock file

Credit goes to Neil over at Navman man forum who helped me work through this

Nice work!
But for future reference : it is not always necessary to "unlock" the desktop or to modify the registry.
You can use a menu that is located in the original Navigation folder and is being started by renaming the exe to the original Navi software.
I've done a couple of times on noname China devices and an old ICN520
Good think about it is that you don't have to mess with the device and can use several GPS programs with the click of a button.
Most missing DLL can be found and included quite easy, same goes for video players or Ebook readers.
But if you need access to the Mio stuff a proper unlock might be better suited. For me a simple menu was so far the easiest and most flexible solution.

Thanks I will try to do this.