Get ready for iOS7 but not for older Iphones

Heralded as the biggest single change to the iPhone's look, feel and performance in the device's history, the latest version of its operating system goes live for existing phone and tablet owners to download and install on Wednesday. Here's what to expect and what to do to make the upgrade a painless experience.

First things first: compatibility
Unlike the unkempt sprawling Android device ecosystem, Apple keeps a tight control over all its iDevices to ensure that they remain useful and compatible with upgrades for as long as possible. However, even older iPhones have their limits and as a result iOS7 will not run on anything older than an iPhone 4. This is where the journey ends for iPhone, iPhone 2 and iPhone 3GS owners, unfortunately.

The upgrade will, however, run on the iPad 2, iPad Mini and any subsequent full-size tablet that sports a Retina Display, as well as the fifth-generation iPod Touch.

Update and backup
Before attempting to download and install the update, make sure that all current apps are up to date. If not, download and install the latest versions and then back up the device to protect its contents. You might want to think about burning a physical disc of photos and videos -- after all these are always the most difficult files to replace. A quick social media post will give you everyone's phone numbers and email addresses again.
Download at home, not on the go
Careful, a full operating system upgrade is a pretty hefty file, so don't be tempted to download it over a 3G or LTE connection. Use the home wifi network or do it via a Mac desktop or notebook then tether the device to transfer the file. Then follow the on-screen instructions. Once installed, check to make sure the important stuff is still there -- contacts, bookmarks, links to cloud servers in apps such as Evernote, etc. -- and then make sure that the phone or tablet is connecting to the right network. Recent Apple OS updates have caused iPhones in particular to use the mobile internet when they should be connecting to wifi and to unceremoniously forget all saved web bookmarks.

Don't let bugs bug you
No first release is ever 100 percent perfect, even from Apple -- look at the Maps fiasco -- so take solace in the fact that the company is already developing alternative versions to fix potential conflicts that will be pushed out very quickly if problems arise. Web logs to the 9to5Mac Apple news and rumors site show that Apple has already built and is testing iOS7.0.1, iOS7.0.2 and iOS7.1 to address problems that could be created when the software is installed on specific devices.