Simple solution how to instal iGO8 or Primo on Mio Moov M400:

1. First of all, make full backup of your device to your PC
2. Because M400 doesnt have SD option, therefore is essential, that you free as much space from Mio device. You can delete all Miomap maps and lang files. They all have .cfg extension. You will find them in dir My Flash Disk\Program files\Miomap\
3. Copy Primo dir on root of the Flash disk (not in any folder!)
4. open \My Flash Disk\Program Files\MioMap\appstartupsec.ini in editor and change this lines:

RelativePath=TRUE
ProcessFile=Program Files/MioMap/MioMap.exe
to
RelativePath=FALSE
ProcessFile=\\..\\My Flash Disk\\Primo\\Primo.exe

* save and exit.
5. Enjoy!