Ok, a lot of people from the US and some other countrys looking after this Tutorial, so i translate this little piece in english. SORRY for my bad English – its not my native Language 🙂
1. Before you flash, load your Smartphone-Battery! And read BEFORE you click the Buttons. Be Patience. Dont Panic – like Douglas Adams says…
2. Download the Nokia Care Software from this Website. Use the newest Version! (my Version Number was 5.0.2012.45.4.5)
3. Install Nokia Care Center (no Rebooting required).
4. Start the Software, double click on “Product Support Tool”, Don’t connect your Phone to your PC!
5. Click in the new Window (the Product Suport Tool for Store) on “File” on the left upper side
6. THen select “Open Product”. Now it comes a new, little Window. In this you have to select your Nokia Phone. Type “RM-820” for the AT&T ROM-Versions or “RM-821” for all other Carrier or unbranded Versions for Lumia 920. You can also select the correct ROM by browsing trought this list (have fun with this – its huge). After Selecting the Lumia-Model click OK!
7. Now navigate your Mouse to “Programming”, (its on the left side at the bottom), then select “Recovery”. Click…
8. Now there is an Window with three Input-Fields (dont know the right description in english, sorry ^-^). And a Button “Find Online”. Click on this – and it will show up a new window with a long list of Firmware-Versions.
Dont worry! For the german ROM, for example, you have to copy (or write) the following code in the field “Code”:
the Variant Name is RM821_CV_DE_VAR241810_black
You see on the “black”-Description, that every color Version of the Lumia 920 has an OWN ROM! So be patient, looking around, try to figure out the syntax (_DE_ in the Filename means Deutschland (Germany), so UK means Great Britain and so on.)
Select your ROM – dont click any other ROM just for fun! Then select Download.
9. Now the Care Suite is ready to download the selected Firmware. ON the bottom right click on “Start” – Now the Download from over 1 GB begins … this will be your new Firmware.
10. After the Download is finished, a new Window will pop out. There will be shown an explanation, what to do now… and NOW you have to connect the Lumia 920 with the PC. (The last Chance to abort the Flashing! Just for the Records.)
11. I need two trys for this, so dont give up: The Pop-Out Window with “Retry” close – and immediately press the VOLUME DOWN and the POWER Keys at the same time (VOLUME DOWN + POWER).
Hold the Keys till your Smartphone will vibrating. Then (be fast) release the two Keys and press the VOLUME UP Button (fast!) and hold this.
When you made it right, your Nokia Care Software on the PC shows “Rebooting”
If not, no Panic. Try again from the beginning of Step 11.
12. The Care Suite says eventually “Wrong Boot Code” or something like this – depends on if you flash the same (or newer) Firmware from your Carrier or flash an different Carrier or unbranded Firmware. Accept this by clicking and the Phone will be flashed.
Attention: Do this on your own Risk! Dont cry, after it bricks your Phone, fire Rockets on your House or something else!