Instructions

• 1). Power off your iPhone.
  
  
• 2). Open iTunes on your computer and plug in your cable. (Do not plug in your phone yet.)
  
  
• 3). Turn on your iPhone and wait 10 seconds.
  
  
• 4). Plug in your iPhone to your computer.
  
  
• 5). Hold the power and home buttons simultaneously for five seconds after the screen goes black.
  
  
• 6). Release only the power button while still holding the home button down. A message will appear on the screen: "iPhone is in restore mode and must be restored."
  
  
• 7). Hold the shift key on your keyboard while clicking Restore in iTunes.
  
  
• 8). Browse and select your .ipsw file on your computer. On a PC, it is found at the path of C:\Documents and Settings\(username)\Application Data\Apple. On a Mac, it is found at the path of Library\iTunes\iPod Software update. If you do not see these folders, enable the hidden folder view.
  
  
• 9). Allow at least 20 minutes for your phone to restore. The process will be indicated by messages on iTunes such as "Extracting software..." and "iTunes is verifying the restoration with Apple." On the iPhone, you will see a progress bar during the process. When it is complete, iTunes will give a pop up message, "Your iPhone has been stored to factory settings, and is restarting. Please leave your iPhone connected. It will appear in the iTunes window after it restarts."