You'll notice if you try to update your iPhone carrier settings using the final version of iTunes 8.2 the .ipcc files are greyed out. In order to re-enabled access to these files you will need to follow the simple steps below.
Press Windows Key + R to open the run dialog. Enter in cmd then click OK
Enter the following command into the Command Prompt window.
"C:Program FilesiTunesiTunes.exe" /setPrefInt carrier-testing 1
Connect your iPhone and click to launch iTunes from your Start Menu.
Select your iPhone from the list of devices on the left then hold down the Shift key and click the Check for Updates button.
Notice you can now select your .ipcc file as it is not greyed out.