Currently Being ModeratedMay 17, 2012 6:57 AM (in response to ipaintmac)
If you forgot the password then there's no other way.
With your iPhone connected and selected, Summary pane, uncheck Encrypt local backup.
In iTunes > Preferences... > Devices, delete your backup.
Right click on your iPhone under DEVICES and choose Back UP.
Currently Being ModeratedAug 26, 2012 3:04 PM (in response to ckuan)
The problem with this solution is that you can't uncheck "Encrypt Local Backup" without giving the (forgotten) current password. Even if you delete the backup, you still can't uncheck it without knowing the current password. It doesn't make sense, but that's how it seems to work. If anyone knows how to stop encrypting the backup after you've forgotten the current password, please post!
To be clear (at least in my case), I don't need the currently encrypted backup. I just want to replace it with a new backup with a new password.
Currently Being ModeratedJul 3, 2013 6:56 AM (in response to PacBlue)
I am in exactly the same place as you right now.
Its crazy you cannot reset this, I need to wipe my iPad but I also need to have a decent backup to restore everything or it could genuinely take days to set up again!