tankk wrote:can anyone teach how to factory reset the nuvi 255w.
my friend borrow my unit and add maps onto it,
now become "can't unlock maps" when start and hang always.
Hard-Reset will not solve your problem. It will only erase setup information and user favorites.
You will need to hook up your Nuvi to a PC and erase the maps in the main memory and/or SD card that your friend added to it.
The offending maps can be located in Main Memory/garmin and/or SD card/garmin directory.
File name is either or combo of gmapsupp.img / gmapprom.img / gmapprom1.img / gmapoem.img .....