I downloaded the Update Wizard. And, thanks to someone giving me a WLAN that worked I downloaded the update image. BUT -- when I run the wizard ... at first it does not automatically connect online, with more trys it never connects online. It does recognize that the n810 is connected. Then I use the manual update by choosing the file that I downloaded. The wizard replys "Unsuported software update file." Then it goes on to say, "The software on your Nokia 810 was not updated, because the update file is not supported by your device." What's happening???

Publicly released firmware doesn't install on prototype devices. Nokia generally keeps the firmware that does work on prototypes internal. There's been some discussion of this in previous threads.