In this post you will know How do I do a factory reset on my iPhone?
Restore iPhone From IPSW With iTunes
An IPSW file or iPhone software file is a firmware update for the iPhone. These files are usually never seen by the end user, since Apple automatically delivers them with the iPhone with iTunes.
Modifying IPSW files has become commonplace to hack an iPhone, although Apple warns against this and the process may invalidate the product warranty.
Jailbreaking is simply the process of installing custom firmware and third-party applications from the iPhone application store. The process of restoring custom firmware for the iPhone is slightly different than that of a normal restore.
Restore iPhone From IPSW Without iTunes
Instructions
1. it supports your important data from the iPhone.
2 open iTunes. Connect your iPhone to your computer via the USB cable.
3 keep pressed the buttons for “Home” and “Sleep” at the same time for 10 seconds.
4. release the button “Sleep” immediately after 10 seconds. Keep holding the “Home” button. If done correctly, iTunes will display a dialog box that informs you that it has detected an iPhone in recovery mode.
5. Click ‘OK’ and leads to the restoration of the iPhone page. This is rather complicated and it may take several attempts.
6. Hold down the “Control” key (or “Option” on a Mac) and click “Restore.” This will open a file browser. Find the custom IPSW firmware and click “Open.”ITunes will begin to restore the iPhone with the custom firmware. A progress bar will indicate the progress of the process and a progress bar will also appear on the iPhone.
A confirmation dialog will inform you of the successful restoration.
Restore your device to factory settings
Open iTunes on your Mac or PC.
If you can't access a computer and your device still works, you can erase and restore your device without a computer.
Connect your iPhone, iPad, or iPod to your computer with the cable that came with your device.
If a message asks for your device passcode or to Trust This Computer, follow the onscreen steps. If you forgot your passcode, get help.
Select your iPhone, iPad, or iPod when it appears in iTunes. For an unresponsive device or one that won't turn on, learn what to do. Or get help if your device doesn't appear in iTunes.
In the Summary panel, click Restore
Restore iPhone in iTunes
Click Restore again to confirm. Then iTunes erases your device and installs the latest iOS or iPod software.
Restore iPhone in iTunes
After your device restores to factory settings, it restarts. Now you can set it up as new.
Conclusion
The Jailbreaking your device, even if legal, may void the warranty on your iPhone. The process of restoration of the normal firmware on the device does not always work well, depending on the device (iPhone, iPhone 3 G, 3GS, 4) and firmware (2.0-4.0). It is also very important to make backup copies of your data before installing the custom firmware. It is also important to read widely about the jailbreaking process before proceeding. If you install the custom firmware, do not upgrade the device directly through iTunes when the new firmware has been released, since this has the potential to “ruin” your device (or make it non-functional).
