Thank you for your help! I have downloaded, I suppose I need some software to flash the nüvi 255. I tried with "updater.exe" from firmware update of the Legend, checked "USB" and get the message "There are no USB Devices available"...
What to do?
Found it: I put the nüvi in preboot mode by holding upper left corner and powered on the nüvi, still holding upper left corner, connected it to the pc via usb, draw the xxxxxx.rgn onto the updater, select usb and it worked!
I got my logo back!
Thank you for all your help!!!!!