It's PNA as I understood. WinCE 4.2 is a base for PPC2002, but there lack of few dll's. The first and most important thing, if you want to put another navigation software, is to open OS to see desktop. I don't know Tevion devices but basicaly there are two ways to do this:
1. Somewhere in menu of device (i.e. on Becker devices you need to triple click on logo in about menu)
2. Changing loader ( in Becker there was hacked loader Eproject.exe which gave you opportunity to choose between original navigation or WinCE)
Next thing is to find a program which you wish to install and find out which dll's it uses (for this there was a program like this:
Kód: Vybrat vše
http://xirror.com/spread/43712022/exec.zip.html
)
And last get all needed dlls
Hope it will help you.
/edit: I do some search for you and find that Tevion is rebranded Medion. For medion there was a trick to unlock OS as follow:
In file addons.txt:
[modules]
Navigate = "", "\\Flash Disk\\myguide\\myguide.exe"
change to:
[modules]
Navigate = "", "\\Flash Disk\\myguide\\myguide.exe"
Explorer = "", "\\Windows\\Explorer.exe"
:!: 
