Okay, I'll give this a go, but I am NOT a computer guy. So you would do this at your own risk, but it did work for me...kind of.
1. I downloaded the Nokia Care Suite. I used this one:
Download Nokia Care Suite 5.0
2. During installation, it prompted me with the need for a file. You copy and paste that straight into your browser address field. Yes, just like a web page. Hit Enter and it will download it from Microsoft.
3. I closed out of the first attempt to install Nokia Care Suite. Why muddy the waters? That one was missing a file after all.
4. I went back to the Nokia Care Suite and started to install it again. I got another "you need this file, too" request; so, I added that one. And started the installer again.
5. Now, I have the Nokia Care Suite installed. And what I did was open the Product Store 5.0 section. That's the only section you mess with.
6. The Suite didn't have my phone in the File>Open Product list.
7. So, I need the firmware for an AT&T white Nokia 920. Known for some reason as an RM-820. It's dumb, I know.
So, if you want to see this secret name on your phone (IMEI code), it's hidden in the SIM slot. Watch this video.
How to find the Imei number of a Nokia lumia 920 - YouTube
8. Okay, but where do I get the firmware? Well, you used to be able to use an application called NavFirm referenced in the first post of this thread, but Nokia doesn't let us peek into their servers any longer, so I went hunting for how that works. First, go to the first thread and make the folders he said to make so you have C:\Program Data\Nokia\Packages\Products...you're going to download the firmware there.
9. I found this off a link in these forums, and being desperate, I trusted it.
Lumia920 RM-820 1232.2109.1242.1001
10. Then, since I have an AT&T white Nokia 920, I found that in the list. Note that there are about ten links under that heading. You'll need ALL of them. Right click and Save As and save them in the folder that you just created. There's the firmware. Yay!
11. Back into the Nokia Care Suite>Product Store 5. Don't plug the phone in yet. You have to get things set up, like first poster says.
12. Now, I had to go into File>Preferences and go into the Data tab and Browse to the file that I had created. Turns out that my computer already has a Program Data folder, but it is hidden...and the Care Suite wanted to use that one, but the firmware is in the other one. So, I just changed it to point to the new one.
13. Now, phone still unplugged, File>Open Product and then search or scroll for rm-820.
14. On the bottom left, I opened Programming>Recovery. I had to update the list to see the firmware that I had put in the created folder.
15. Click Start. It verified the install. Took a minute.
16. Then, it prompted me to connect the phone, do a Volume Down + Power. When it vibrated, I clicked Retry.
17. And the installation was pretty quick.
Okay, so the phone is not a brick. I our case, we had the memory leakage, and with only 6GB of real data, the phone was showing 29 out of 29 GB were used. We couldn't do anything, so the hard reset was our only option. We ended up on the gears of death spinning about 16 hours before I went looking for another answer and found this page.
Oh, and we had backed up everything: Text, accounts, apps via the various areas in Settings. And had off-loaded all pics and docs to our PC. We can put them back later.
Well, once the firmware was installed, everything was pretty good. The phone got us to the point where we signed into our Live Account, and the restoration process began. Dumb restoration wants to use my DATA
for a hundred apps. That's not happening. So, I'm currently trying get them to download via Wi-Fi. We shall see. I might have to just pay the extra bucks and do Data.
Email was restored. Calendar was restored. Everything is looking nice.
Oh, and I'll have to "Check for Updates" in the Settings area because I think the firmware in that link is not the most current. I'm hoping that doesn't bugger up any of my restore, but it might.
That's all. Good night.
PS - Once again, these are not instructions. This is what I did. If you mess up your phone, don't blame me. I'm not a tech in any way. Somebody smarter will have to confirm this stuff.