If I connect my iPod with my computer and start up iTunes, the Device button does not show up (this has nothing to do with the sidebar, tried that already). I had problems with iTunes before, I uninstalled it and reinstalled it, maybe something went wrong, What to do?
iPod touch (4th generation), iOS 6.1.5
Try
iOS: Device not recognized iniTunesfor Windows
I would start with (not clear yo removed an reinstall all Apple software)
Removing and ReinstallingiTunes, QuickTime, and other software components for WindowsXP
or
New cable and different USB port?
Runs this and see if the results help with determine the cause
iTunesfor Windows: Device Sync Tests
Try on another computer to help determine if computer oriPodproblem
iTunes does not recognize my iPod
