Assuming you don't have the original library files backed up as well you'll probably need to take this approach for each of the iOS devices.
You should be able to:
- Backup the device to the new installation
- Transfer your purchases into a newly authorized library
- Recover any other media using third party tools as suggested in this post (unless you already have everything)
- Restore the device from the backup
This process should switch the association of the device to the new library, preserving the data and settings in your apps.
May also be prudent to attempt a backup to iCloud directly from the device before you start... Settings > iCloud > Storage & Backup > iCloud Backup > On. It won't save any media but it would preserve the general account settings and documents in case anything goes wrong while you are trying to extract your other data.
For the nano's reloading them will take time, and you may loose game scores (if applicable), but it shouldn't cause too much of a problem.
When you get it all fixed, make a backup!
Still stuffed here am afraid. Am just working on one ipod for now as i dont want to stuff up my other 2 nano's and 2 itouches.
This is what i have now done:
Uninstalled itunes and deleted all associated files
I had to create a new library for my 2G nano (as it couldn't find the old library as am on a new hdd) - i tried to cancel creating a new library but it wouldn't work so tried to start fresh
My nano will show in itunes (although the itunes shows it a good 5 mins after connecting when the nano is nearly automatically connected)
I added an album to my "new" library and tried to sync it to the nano - it starts the process (although there is no acknowledgement on the nano itself at all) - after about 2-3 minutes i get 2 consecutive pop-ups <ipod cannot be synced - required disc cannot be found> + <ipod cannot be synced - required folder cannot be found>
The syncing process on itunes main page just scrolls through syncing > ok to disconnect device > then resumes syncing again
I have gone through the diagnostics in itunes and it does show it can talk to my nano so i am totally at a loss here.
I have tried to restore my ipod via itunes but that doesnt even work
Any assistance that doesnt involve a sledgehammer woyld be greatly appreciated