HI

Please bear with me as I am a newbie and a little confused...I have a Garmin Etrex Legend GPS and wanted to put some maps on to it. I have a 32GB SD card and have downloaded the Lake District IMG file, and loaded this onto the card, yet when I turn on the GPS there is no sign of the map other than a symbol of a house where the lake district would be on the basis sat nav map. I've seen other threads where people are talking about downloading mapsource etc. Is this where I have gone wrong and you have to download some other software to get the maps to work. Once again apologies for sheer ignorance!