Download Latest Device OS 5 from this link
Backup your device first, using Desktop Manager > Backup.
Close Desktop Manager upon completion.
Download the OS file to the PC then install it to the PC by running (double clicking) the file you downloaded.
Go to c:\program files\common files\research in motion\apploader and delete the file named “vendor.xml.”
Plug in BlackBerry and double click on “Loader.exe.” It’s located in the same place as the above vendor.xml file.