To obtain the latest operating system for your Black Berry device, first check your wireless carrier's website.This is the best way to get official RIM OS software.You should click Next and then on the following screen choose the country in which you're currently located. When the install process is complete, the program will ask you if you want to start the Black Berry Desktop software.Fill in the check box next to this option and then hit "Finish." Install OS4.5 onto your computer When the Desktop Manager software opens, plug your device into the PC via USB cord.Save the latest BBOS onto your Windows-powered computer If you decide to download and install an unofficial version of the Black Berry OS, you should beware that you're doing so at your own risk.Beta operating systems are not officially released for good reason: They're often full of bugs and could potentially void your warranty or worse, render your Black Berry unusable.Installing a New Black Berry OS will return some of your custom settings to the default options and may require you to log back into and unlock certain applications.
Next you should ensure that your PC is running the latest version of the Black Berry Desktop Manager, which is v4.5.(Read, "How to Reload the Operating System on a Nuked Black Berry," if you ever find yourself with a bricked 'Berry.If you do decide to install unofficial software and it's from a carrier that isn't your own, you should be sure to ditch the software's vendor XML file before beginning installation.To start a new operating system install, you'll need your Black Berry, an Internet-connected PC, a USB cable and about an hour and half of free time—50 minutes or an hour for the upgrade process and 30 minutes or catch-up time afterwards.Mac users beware: RIM doesn't currently offer the Black Berry Desktop Manager software for Apple computers; however, industrious Mac owners running Parallels and who have a copy of Windows have been able to upgrade their Black Berrys via Macs, though the process can be a bit clumsy.