1. First try going to Settings/Device/Sync Options, then toward the bottom left side there is a delete all content button click it and then try to sync your device.
2. If that didn't work go back to the same page and click the button beside it that says forget this device. Next unplug your Zune and replug it in to you PC. It should give you a screen asking if you want to connect as guest or make your zune you main.
3. If that doesn't work the harder route is to delete everyting off your device then reload it. Follow this link here. This isn't recomened though. I did have to do it before but my zune worked fine afterwords.
Live Long or not At All
