Dear all I'm not able to upload my registered track from the actual route I've walked to my PC. I've checked off the red cross (exit function with saving), but I don't know which file to upload for logging and analysing the NAV-data. I can't find this information in enough detail in any User manual or instruction film on internet or on my Adventurer 2800. Please help me out here.

You need to save the data on the 2800 to a file using "Overlay" -> "Save as..."
Then, the file you saved will appear in the UserData folder on the 2800 when you plug it into your PC.
You then import that file into MM on the PC.