Firmware
No need to be nervous, but be certain you download the update for the right unit. West sells a "76cs Plus" that apparently has different firmware than the regular 76cs. I think the "Plus" version has West Marine written on the unit near the top. The firmware at Garmin's update site for the last version differs between the two unit models. Assuming you have installed Mapsource and/or the USB drivers, just download the update file for your unit, put the update file in it's own little folder, clickon theupdate file to "extract" the files that will be used and place them in thesame folder, attach your unit to the computer USB port, double click the "Updater.exe" file that appeared after the extraction. The update will take some time and there will be some what appears to be dead time where nothing seems to be going on. Just wait it out. You 76cs should turn off when the update is complete and you will be notified by the computer. Full instructions are provided when you download the update.Oh -- Do not do this when you might have a power outage. That might result in major headaches.I have updated the firmware on three different units many times over thepast year and have had absolutely no problem other thana bit of a scare each time when things appear to stop dead in the middle of the process. Again, just be patient.The newest update for Mapsource can also be found at the bottom of the Garmin update page. There have been some significant improvements in this software over the past year.