When trying to sync my mom's 16 GB WiFi-only iPad to her laptop (Windows 7 Home Premium 64-bit) with iTunes (64-bit version), we get to the end of the "backing up" part and it spits out the error "Cannot sync device due to an internal device error". It also constantly treats the iPad as if it's never seen it before, asking us if we want to set it up as a new iPad or restore from a backup.
We tried doing the restore from backup and got the same error, and setting it up as a new one simply gets us to the end of the backing up phase before spitting out the error.
We've already tried the basic troubleshooting tips (Restarting both the computer and the iPad, then both again at the same time, uninstalling and re-installing iTunes, etc.), but haven't restored the iPad to factory defaults, as my mom is worried about losing her apps and paid-for music.