When you plug your iPod into your computer, iTunes may automatically sync music and other data to it. This setting is inconvenient if you use multiple computers or if the data on your iPod is different from that on your computer. Stop your iPod from syncing by changing the settings in iTunes, then configuring the device for manual syncing. This allows you to plug your iPod into any computer without worrying about losing data.
Open iTunes. Click on "Edit," then "Preferences." Click the "Devices" tab and check the box next to "Prevent iPods, iPhones, and iPads from syncing automatically."
Plug the iPod cable into the iPod and the computer. If the computer doesn't recognise the iPod and show it under iTunes' "Devices" list, unplug and reconnect the USB cord. Choose "Cancel" if a pop-up box asking to sync appears.
Click on your iPod in the "Devices" list, then click "Summary." Check the box next to "Manually manage music and videos" to put your iPod into manual mode. Disable syncing for other types of content by clicking their tabs and unchecking the "Sync" boxes. Click "Apply" to make the changes permanent.
Deselect the box for "Prevent iPods, iPhones, and iPads from syncing automatically" if you still want to use automatic syncing on other devices.