Follow these instructions exactly, and you should be able to install any OS 4.x on your device.
Destkop MANAGER BE INSTALLED ON THE PC (for users with Desktop Manager 4.6 or Higher disconnect the internet from your PC before the upgrade, as these versions check the online database of operator (most, not all ) and if the OS they want to upload is higher than that currently supports the NOT operator will then be able to update your computer by deleting the vendor.xml NI)
Download, Install and Run the OS on the PC (the OS has to be compatible with the model of your BlackBerry)
Delete the vendor.xml file (in Windows XP is achieved by following the following path: C: Program Files Common Files Research In Motion AppLoader)
Disconnect / Disable the Internet before connecting the BlackBerry to the PC and open the DM
Make a backup of your INFORMATION!, Is the best thing to have on hand in case something goes wrong.
Check you’re using the latest version of Desktop Manager (Desktop Manager), but you download it HERE
Download the latest version of the OS for your device.
Install the OS 4.x. Exe file you downloaded, if this version is supplied by your operator then jump to step 5. Now if you downloaded an OS for your device but from another provider, then proceed to step 5.
Delete the file “vendor.xml”, its location is C: Program Files Common Files Research In Motion AppLoader, or the easiest is to search the file on your computer “vendor.xml” and find delete .
Connect your BlackBerry to the computer, if necessary write the password on your BlackBerry and click OK.
Open the Desktop Manager (Desktop Manager), you should recognize that there is an update available for your device (remember that the vendor.xml, should have been removed for this to work)
When the Application Loader there finished analyzing the configuration of the BlackBerry device, the selection screen device applications will appear, showing the OS and applications available for installation, applications with check marks are those installed (you can choose which will be).
But you made a backup, what should you do now.
Follow the prompts on the screen, and you should have your OS 4.x installed 30 to 45 minutes.