There's no way to lose any information in a theoretical upgrade, but we recommend backing up your iphone in case of a precaution.
1. Direct upgrade on mobile phone
Apple has been pushing the OTA upgrade for iOS 7 this morning, and if you are an official version of the iOS 6 system, you can now see the update logo on the setup. Click "Settings"-"General"-"Software Update", Direct point upgrade is good, is not very simple?
OTA upgrade
NET speed is ideal, download plus upgrade will be done in 20 minutes, but ... At present, more people may upgrade, the server pressure is huge, so download slow or even download failure is possible. Pro, it's like the traffic in Beijing last night, it's good to avoid the peak.
Already upgraded iOS 7 system has been upgraded to the iOS 7 system
In addition, users who have escaped must not be upgraded directly in this way, you need to go to the original iOS 6 6.1.4, then open itunes, hold down SHIFT, and then shift to select the downloaded firmware to restore the status before the jailbreak, but everything in the phone will be lost, so be sure to back it up first.
Note: Before upgrading the IOS7 system I need to back up the data in the mobile phone, or upgrade your mobile phone in the newsletter, SMS will be cleared Oh, so we first backup as well.