Thanks for the answer, but I don`t see v17 in this link.

I`m not looking for "Key CD", v17.1 or some other version of OS.I`m looking exactly v17 3-1/30 for MKIII computers.

As I wrote in my first post, I need it to try overwriting flash memory.If there is some other way, I`m open for it.

I was thinking of some way to copy flash memory from other MKIII computer and try to write it in my computer with NavCoder, but I`m not sure is it possible.

At the moment, my MKIII does not remember adjusted settings (color, dimmer and showing BC on radio screen) after red led turns off, so I suspect corrupted flash memory.Everything else works well.I tried software update with at least 3 version of OS, but only thing I get is screen "CD Navigation software loading" and nothing happens.