Garmin often releases updates for devices to improve performance, correct bugs or add new features. The internal operating system software is separate from software such as mapping that may be on some handheld units.
The software update may erase user data that has been saved to the device. Before performing the software update, back up all userdata (waypoints, routes, and tracks). For instruction on backing up userdata from the device, please refer to the FAQ titled "How do I backup user data from my Garmin USB Device handheld?"
To update your device's software a program called Garmin Express will need to be downloaded and installed*. Once the program has been installed, please follow the prompts to add your device and then install any available updates.
*For older Garmin Mode devices or units with a serial port connection, a program called WebUpdater will need to be downloaded and installed instead. There are instructions at the bottom of the download page that will help with the installation of the program. Once the program has been installed, please follow the on screen prompts to complete the update process.