Today after waiting a lot, I upgraded my factory unlocked iphone 4 to firmware 4.3.3, fortunately the jailbreak tool redsn0w was already out yesterday which now supports the latest ios version 4.3.3 right now. The entire procedure was quite simple, as I have previously did it as well but this time I was very peculiar about my previous iphone data should be backup and can be restored back to the device after up gradation to ios version.
I am not going to write a full guide on how did I do it, as there are already many guides available on web on many websites, rather I will stress on some things you should know and remember while doing all this as all other so called iphone jail breaking guides websites on web normally don’t tell you what may go wrong and also they don’t tell you how to get back your data after the upgrade.
Before you decide to upgrade, connect your iphone, ipod to itunes and take a full backup of the device as shown in the image below.
Once the back up of your apple device is done, then download the ios firmware version using direct link to the apple servers from here. Now you will need to restore the official firmware on to your device through itunes restore feature, make sure that your iphone is connected to your computer running itunes, press shift and click the restore button in iphone, ipod summary section then you will itunes restoring or flashing your device with the ios official firmware as shown in the image below.
Once your device has the upgraded firmware installed, it might ask you for setup a new device or restore the previous backup, you should select setup a new device but make sure to backup or copy the itunes backup data folder at the following path as per operating system.
On a Mac: ~/Library/Application Support/MobileSync/Backup/
On Windows XP: \Documents and Settings\(username)\Application Data\Apple Computer\MobileSync\Backup\
On Windows Vista and Windows 7: \Users\(username)\AppData\Roaming\Apple Computer\MobileSync\Backup\
To further carry on with the jailbreak procedure, follow this guide here. Once your device is jailbroken you can easily restore all data, apps, settings you have configured on your iphone, ipod touch by connecting it again with itunes and then select restore the last latest backup data on your devices as shown in the image below.