i have the tomtom 540-tm, i have never updated the maps and am not computer savy. when i tried to update i quickly realized all the info i originally had is now gone. I have tried off and on for months now with no success. I believe i have the correct tomtom home downloaded but now when i connect my device it says "your memory card is write protected please remove write protection DesktopLib/volume/write protected" this seems like a foreign language to me and i am desperate to be able to use my devise again PLEASE if anyone can help me id really appreciate it