I cannot get Ipod Classic to sync in iTunes

Hope someone can help me. I have an iPod Classic that will not sync any of my music to it. I just got a new computer with Windows 8 (before I had Vista). Windows recognizes the iPod and so does iTunes. It starts to sync, the wheel turns for about 20 seconds then says 'eject before disconnecting". I've tried restoring the iPod, uninstalling and reinstalling iTunes, and I've run the iTunes diagnostics. On the sync test is says no iPod found. I've checked to make sure iTunes was enabled and I've also made sure new computer was authorized. Any ideas?