Before updating to iOS 7, I highly recommend that you navigate to Settings > iCloud > Storage & Backup > Back Up Now and do a backup of your data. If you're upgrading by installing the update through iTunes, update to the latest version of iTunes first (In OS X, go to the Apple Menu > Software Update and check for updates), and then make sure to initiate a backup in Tunes under File > Devices > Back up.
Take this step seriously. It's easy to do and if something goes wrong in the update, your data is preserved.
To install iOS 7, there are a few options. From an iOS device, you can navigate to Settings > General > Software Update and run the update from there. After the download is complete, your device will update in place, leaving all of your settings, data and apps intact.
If you upgrade by connecting your device to a computer running iTunes, you'll have the option to either Restore or Upgrade. The Upgrade option leaves your settings, data and apps in place; the Restore option deletes everything on the device first before installing a fresh operating system. If you've been having issues with your device, or if you've modified the OS in ways Apple hasn't sanctioned (such as Jailbreak), then a Restore may be the best bet.
The Lock Screen shows very little except the time and date, and the slide to unlock message.
Welcome to Apple's future
After the installation is done and your device has restarted, you get a multi-language welcome screen. Right off the bat, the brighter interface is noticeable; the white screen and new fonts are a hint of what's to come.
With a Slide to Unlock swipe, you're launched into a Set Up Assistant that walks you through the process of configuring basic settings such as connecting to a local Wi-Fi network, toggling on/off Location Services and, if you're starting from scratch due to a Restore, options to set up your device as new or restore from backup via iCloud or iTunes. Restoring from backup brings all settings, contacts, mail accounts, iTunes purchases, etc. to your iPhone. That way, when the restore is finished, your device is just as it was.
After a few simple setup questions, you'll be dropped off into the new Home Screen. Welcome to iOS 7.
A new home (screen)
At this point, as you scan iOS 7's new look, you're either smiling or frowning.
When this new design was first revealed in June at Apple's Worldwide Developers Conference, various Mac techies debated whether it was a good idea. My take now is the same as in June: iOS 7's color scheme looks as if the folks behind Flower Power iMac and the new iPod touch models had stormed Apple's design office, raised their minimalist, multicolored pirate flag and looted all things shiny in the old iOS.
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