Once logged in, locate the system upgrades section, check to see if there's an OS version that's more recent than the one you're currently running, and if so, download and save it to your PC's desktop.
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.
You can also employ the Help Me screen shortcut to determine your current OS version by hitting ALT, SHIFT and the letter H.
It's a good idea to switch back to an official RIM theme if you're using a third-party option, at least at first, because some features of non-official themes won't work properly on the new OS.
And it's worth noting that applications are meant to run on specific OS version so they may not work at all after you upgrade.
If you don't delete the other vendor's file, the software won't be able to install the software on your carrier-locked device.
You can visit Crackberry.com's OS4.5 Beta forum for discussion and help should you run into issues.
Keeping up to date with the newest operating system (OS) software for your smartphone ensures that you have access to all the latest and greatest features and performance tweaks.