I am also a technician and suggest you do the following.
Download and install BlackBerry Device Manager v4.2 (English)
This will install the Application Loader as well as all needed drivers. The Application Loader is under:
"C:\Program Files\Common Files\Research In Motion\AppLoader\Loader.exe"
Now you have two choices. Either download and install all the firmware you need, or install the latest firmware you can find for each model you support, and rename the file vendor.xml "C:\Program Files\Common Files\Research In Motion\AppLoader" after each model you install - so after you install Cingular's 8700c firmware, rename vendor.xml
. Once you've installed all the models you need, copy the most recent vendor,provider.model.xml to vendor.xml - it should have the most current definitions for all vendors and models.
"C:\Program Files\Common Files\Research In Motion\Shared\Loader Files"
with names typically similar to the name of the original file. For example, the file "8700M_PBr4.1.0_rel529_PL126.96.36.199_A188.8.131.527_Cing ular.exe" installs to the subdirectory "8700-v184.108.40.2067_P220.127.116.11".
The other option is to just install the latest version firmware you can find and have NO vendor.xml. Application Loader will be able to detect which model is attached and use the appropriate files. This is far simpler.
Now, this should all work fine, but upgrading options are listed on pages 13 and 14 of the Upgrade Guide
Hope that helps.