I am trying to upgrade my father's i Pad 1 to i OS 5 using a brand new Windows 7 profile on my laptop.
When I enable them, i Tunes warns me that by doing that the i Pad content will be by the computer content, which would be absolutely nothing. First, make sure that i Tunes is signed into the i Pad owner's Apple account. Once the update is installed, it will then restore all the prior apps, data, music, movies, pictures and books the tablet. (This is based on my experience upgrading an i Phone 4 from i OS 4 to 5.) Two hours later, a near bricking of the device later, many driver installs and reboots and a couple error codes later, much much clicking later, I now have an i Pad that has "magically" lost 11 GB of data, plus the entire configuration of all the home screens.
With i Tunes, you can manage the content on your i Phone, i Pad, or i Pod by manually syncing specific items to your device.
If you have i Cloud Music Library turned on, you can't manually manage music, but you can still manage videos using the steps below.
Apple today acknowledged i Tunes users who claim the software deleted their music files, saying it will issue an update to i Tunes next week that includes additional safeguards.