After the advent of new generation mobile phones such as apple 5, Apple's system software is also continuously upgrading. Many users of apple 4 use the IOS 4.0 system in their hands, which is usually carried by Apple 5. However, due to the immature technical conditions, they can only bemoan. Here is a detailed introduction to Apple 4's brush process:
Step 1: first, Download iTunes 10.5 software and new system IOS 5.0 on the computer in advance, then connect the computer with your own Apple 4, and back up the important data in the mobile phone in iTunes software, such as contacts, email accounts, SMS, photos, etc., to prevent the loss of important data after the update of the mobile phone. You can start the update after you have done the preparations before escaping from prison.
Step 2: enter DFU mode before updating the mobile phone, turn off Apple 4, press and hold the on / off key and home key at the same time, and then press and hold home key for ten seconds to enter DFU mode. Then press Shift + update on the computer and wait three to five minutes During the update process, the phone will remain in a black screen state until the phone is automatically turned on after the update.
Important note: after entering DFU mode, connecting iTunes will pop up a pop-up box, indicating that the device driver software is being installed or that iTunes has detected an iPhone in recovery mode. You need to backup to recover your iPhone before using it with iTunes. Please ignore the prompt box and press shift to update.
According to the above operation, even if you are a technical rookie, you must be able to brush your apple 4 accurately. Since then, there are all kinds of new systems that can be installed through their own capabilities.