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 can visit Crackberry.com's OS4.5 Beta forum for discussion and help should you run into issues.
Next you should ensure that your PC is running the latest version of the Black Berry Desktop Manager, which is v4.5.
With the official release of Black Berry OS v4.5 on the horizon—various beta, or test, versions of the software are already bouncing around the Web—we thought this would be a great time for a Black Berry OS tutorial.