Device operating system releases are "released" by specific carriers once they have certified and trained their support techs, but still, you are able to load to any carrier's same model by following the instructions below.
You can install v4.5 downloaded form Tmobile Germany.
See the link below, for the download and simple installation instructions.
First locate your carrier and the OS file you wish to use.
http://updateservice.t-mobile.net/blackberry/login
(the site is in german, so click on FREE DOWNLOAD > then Endgeräte > BlackBerry > Device Software > 8800 etc., and download the file.
Do a backup of your device first, using Desktop Manager > Backup. Close Desktop Manager upon completion.
1. Download the OS file to the PC then install it to the PC by running (double clicking) the file you downloaded.
2. Go to c:\program files\common files\research in motion\apploader and delete the file named "vendor.xml."
3. Plug in BB and double click on "Loader.exe." It's located in the same place as the above vendor.xml file.
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3. Install free BlackBerry Protect today for backups of contacts and data.
