I have synced my iPhone to a different computer before but now I want to sync it to my new computer. Since there are no tick boxes if I add a song to my library it will not sync to my phone.
If you haven't migrated your library properly from your previous computer see Recover your iTunes library from your iPod or iOS device.
To show check boxes use Edit > Preferences > General tab > Show: List view tickboxes,
I'd recommend syncing with selected playlists rather than relying on check boxes.
tt2
There are no tick boxes showing next to the song titles in iTunes on my PC.
