Thanks for checking although using a .unl file didn't seem to work previously. Due to the size of GB Discoverer it has to be installed on the sd card so from what I understand the sd card id needs to be used to generate a code using JetMouse Garmin Keygen v1.5 with checksum fix, this is were I think I was having a problem as the number I used was the 10 digit number printed on the micro sd card, I have read lots on this forum about obtaining the sd card id and am therefore unsure if I have been using the correct number to generate a code I also tried the Garmin Dakota 20 serial number but that didn't work either. Any ideas on how to make sure I am using the correct card id number would be much appreciated. Many thanks