Hi there.
I have spent the better part of this morning trying to get my Iphone 4S, iOS 6 beta operational again after the beta expired yesterday. I know I could just restore it to factory defaults but that would leave me with an empty device. Since I had no backup I needed to update to the release version of iOS 6 without data loss.
Which I was able to do. 🙂
1: Download the correct .ipsw from Apple Link(this is ios 6 for the 4S)
2: Start iTunes
3: Connect your iphone and wait until it is verified (and that it fails because the beta has expired)
4: ALT-Click (Mac OS) the "Check for Update" button (I do not know the equivalent combination for Windows. Just try)
5: In the Open-File dialog box find and select the file downloaded under step 1
6: Wait for your Iphone to be update to the lastest iOS 6 version with all your data intact!
I was close to crying this morning when I discovered my beta has expired leaving me with the choice of knowing that I had my data on the phone, but with no way of accessing them - and reseting the phone to factory defaults to make it usable but in the process losing all my data.
These few steps got me a working phone with my data intact. 🙂
Good luck.
//Ulf Thomas
Message was edited by: UlfThomas to remove spelling errors