My C-drive is full(has 3gb free) and itunes fails to backup my ipad (32gb) when trying to install the new iOS. OTA updates keeps on failing aswell.
How do you change the default backup location of your ipad?
Moving the iOS device backup location
Open a command prompt by hitting the start button and typing CMD<Enter> in the search box that opens up, or with Start > Run on older Windows.
To move the current backup folder from C: to D: (for example) type in this command and press <Enter>
Move "C:\Users\<User>\AppData\Local\Apple Computer\MobileSync\Backup" "D:\Backup"
Where <User> is your Windows user name.
To make iTunes look for the data in the new location type in this command and press <Enter>
MkLink /J "C:\Users\<User>\AppData\Local\Apple Computer\MobileSync\Backup" "D:\Backup"
If your preferred drive has a different letter or you already have a folder called "Backup" then edit "D:\Backup" accordingly in both commands.
If you have Windows XP then you'll need a third-party tool such as Junction to link the two locations together instead of the MkLink command. The source folder is C:\Documents and Settings\<User>\Application Data\Apple Computer\MobileSync\Backup