These steps will guide you to upgrade your blackberry OS. just follow it.
1. Download and install to PC the latest version of Desktop Manager from here: ( BlackBerry Operating System Downloads )
2. Download the new OS you want and install it to the PC
3. Open Desktop Manager and do a complete backup of your current device.
4. Delete the vendor.xml file located in c:\program files\common files\research in motion\apploader
5. Plug in BB and open Desktop Manager
6. Select Application Loader
7. You will be prompted to upgrade
Friday, July 24, 2009
How to Upgrade Blackberry OS