iPod won't backup to computer, "not enough free space"

I recently got a new computer. When trying to do a backup of my ipod to my computer it alerts saying "not enough free space." I have deleted files. My C: has 561GB available space. Touch is 1st or 2nd generation running 5.1.1. PC with Windows 8. iTunes 12. I can not figure it out. Please help. I rebooted both computer and ipod. Same alert when trying to backup via plug in or wifi. Thanks in advance.