A 2nd generation iPod is the second model of that particular iPod, such as the Nano, Touch or Classic. As with other iPods, there will periodically be software updates available for all 2nd generation iPods. These updates can be downloaded and installed directly onto the iPod. In order to update the software on a 2nd generation iPod, you will need to sync that portable device with the iTunes software that is installed on your computer.
Connect the 2nd generation iPod to the computer using the device's USB cord.
Click the 2nd generation iPod name under "Devices" on the left portion of iTunes. Two buttons will become visible inside the middle iTunes window.
Click the "Check for Update" button. If an update is available, an alert will open in iTunes.
Sign into your iTunes account if you are asked to do so, and then click "Download" to download and install the software update on the 2nd generation iPod.