The two iOS 5 betas that have been released to date aren’t exactly the most stable. Bugs, random crashes, phone reboots, and problems with GPS are just a few of the issues that have been reported by users since the beta launched. If you happened to install this beta on your everyday phone or iPad, some of these bugs might just be a little too much.
If you upgraded to iOS 5 and would like to go back to good old stable iOS 4, it’s not quite as easy as you might think. Follow along to learn how — keep in mind that this process requires iTunes 10.5 beta, which you probably already have since it was required to upgrade to iOS 5 in the first place.
Make a backup
The first thing you’ll need to do is make a backup of your iOS 5 install. This will save your apps, settings, text messages, and call logs so that you don’t have to restore everything once you downgrade. Plug your iOS device into your computer and open iTunes, then right click the device and select Back Up. A new backup file will be made.
Put the device in DFU mode
The downgrade will not work unless your device is in DFU (recovery) mode, so the next step is to do that. Turn your device all the way off (not just sleep), then hold both the power and home buttons for 10 seconds. After 10 seconds, release the power button and continue holding the home button down until iTunes tells you that the device is in recovery mode.
Install official firmware via iTunes
Next, we will use iTunes’ restore firmware feature to restore the stock firmware. Open your iOS device’s page in iTunes, and click the restore button. It’s going to ask you if you want to restore from a backup or restore iOS 4.3 directly. Pick the second option to restore 4.3 directly, and iTunes will begin the process of your firmware restore.
Restore your backup
Finally, restore the backup that you made with iOS 5 when you are re-setting up your iOS 4 device. It won’t restore any parts of iOS 5, just the settings and apps you had. From then on you should be back on a more stable iOS 4 and your phone should work with less problems again.