How to erase iDevice backups

Option 1: delete backup under iTunes Preferences

1. Open you iTunes account
2. Go to the iTunes preferences (in Windows this is under "edit --> preferences" and on a Mac it's under the iTunes on the top left of your screen --> select "Preferences"
3. Click on the tab that says "devices" --> this will show a list of any iDevices that you have synced with iTunes (you may just have the one)
4. Select your iDevice from the list --> then click "delete backup" button. This will delete the old (and what appears to be corrupted) backup.
   
5. Plug in your iDevice to your computer. This should do the trick!

6. Option 2: Delete backup manually from your computer

   Go to: http://solution2everything.blogspot.in/2013/07/if-youve-looking-for-location-of-your.html
   This describes how you find the location of your backup for your iDevice on your computer.
   
   1. Following the directions in this link, locate your iDevice backups on your computer.
   2. Delete them (drag to trash)
   3. Then resync your iDevice

   Option 3: Reset factory settings

   If that doesn't work, then it is likely a problem with the iPod itself. To fix that, reset to the factory settings -- which is a pain because you lose all your files and have to start from scratch (but all the apps that you have purchased/got free will still be in your iTunes)
   
   1. Connect your iDevice to your computer
   2. Open iTunes
   3. Select your iDevice in iTunes (under the "Devices")
   4. Click on the "restore" button
   5. This will reset your iTouch so it is as if you just opened it for the first time out of the box.