Hey VPII,
Dowload 540 software
Installation Instructions
Click on "Download" and choose to save the file to your computer.
Choose a location where you can easily find the file, such as the 'My Documents' folder or 'C:'.
Once the download is complete, go to the location where you saved the file.
Double-click on the downloaded file. This will automatically extract the files to C:\Garmin and run a program to transfer the software update to an SD card.
System requirements:
IBM-compatible PC running Windows 2000 or later operating system and an available SD card reader.