[Nokia Lumia 520 Guides, News, & Discussion] ZeroTheSavior:
If you're one of those who has never touched a windows phone before, this guide is for you.

Prerequisites: Windows Device Recovery Tool and internet access on your phone.

Warning

If you've updated to Win10 using insider and you're not getting any updates for fall creators update, follow the guide from start to finish. Don't skip to step 3 just because your phone is already on Win10. Having a carrier branded ROM can cause issues.

STEP 1: Flash unbranded ROM

Since AT&T never provided a version above 8.10.12393.890 and the insider program has been shut down, you must flash an unbranded ROM before you can upgrade to Windows 10. PHONE/SIM WILL NOT WORK, so if you care about receiving phone calls then don't bother.

1. Download an unbranded ROM here, "RM-915 VAR BR CV": https://www.lumiafirmware.com/model/RM-915/hwid/059S2X9

1b. Click 3058.50000.1424.0002

1c. Just download the ffu. You don't need anything else.

2. Open an admin command prompt, cd "%ProgramFiles(x86)%\Microsoft Care Suite\Windows Device Recovery Tool"

You might want to rename your ffu file to firmware.ffu to make it easier to type since you can't drag files into an admin command prompt.

3. type thor2 -mode uefiflash -ffufile "C:\SomeLocationHere\yourfile.ffu" -do_full_nvi_update -do_factory_reset -reboot

Where C:\SomeLocationHere is the location to the file, of course

3b. If your phone is stuck in flashing mode for some reason type "thor2 -mode rnd -bootnormalmode"

4. After it installs and reboots, set up the phone again. Yes it will be in another language. proximo means continue. You can probably get through the setup without too much issues. Aplicativos means it's installing the apps, just wait 15-30 minutes and it should be done.

5. Turn on airplane mode or it will reboot every 10 minutes. Yes, really. Head to settings, idioma, add "Ingles" or your preferred language, hold down, press the second option (move up), hold down on portugese, press the first option (remove), press the reboot button.

6. Head to the software update section and update your device. It will take an update for an update to show, so be patient! If it says there are no updates available after an hour, please message me or if you're feeling adventurous you can try with "RM-915 VAR APAC AU TELSTRA" instead of the Brazillian ROM.

STEP 2: Update to Windows 10

Make sure you've done step 1 so your software version is 8.10.14219.341 or newer, since you cannot use SOUP on an older version.

1. Get SOUP from this guide.

2. Double click run_en.cmd and follow the rest of the instructions.

STEP 3: Interop Unlock:

1. Unlock the bootloader, enable mass storage, and root using this guide. Yes, you can use the .ffu for Windows 8.1 to unlock your Windows 10 Nokia.

2. Go to settings, search developer, tap the result that says "For developers".

3. Set it to Developer mode.

4. Set the date back to a time before Nov 24 2018 and reboot. The Interop Tools cert expired so it won't install if it's past that date.

5. Download Interop Tools, extract it, then copy it to your phone's storage over USB.

6. Open the File Explorer app on your phone, navigate to the directory you copied over, and install the files in /Dependencies/arm. Note that there is no installation progress indicator so please wait 30 seconds-1 minute before installing the next one or the app will not install.

7. Install the InteropTools appxbundle.

8. Open Interop Tools, go to the interop unlock section

8b. DO NOT TAP THE STORAGE UNLOCK SWITCH!!! USB WILL STOP WORKING! (You can turn it back off anyways if you accidentally turned it on)

9. tap the interop unlock switches and restore NVDK. Your phone is now Interop Unlocked!

STEP 4: Update to Fall Creators Update

You need to make your phone appear as a Lumia 950 XL.

1. Open Interop Tools, go to the registry editor

2. Navigate to HKLM\SYSTEM\Platform\DeviceTargetingInfo

3. Change the values to the following:

PhoneHardwareVariant : RM-1085

PhoneManufacturer : MicrosoftMDG

PhoneManufacturerModelName : RM-1085_11302

PhoneModelName : Lumia 950 XL

4. Reboot

5. Check for updates

6. Update the phone (You might have to wait a few hours before any updates appear)

7. Repeat steps 5 and 6 until you reach 15063

If you ever want to change back, the original values are:

PhoneHardwareVariant: RM-915

PhoneManufacturer: NOKIA

PhoneManufacturerModelName: RM-915_nam_usa_228 (Your phone might be different, best to keep it backed up!)

PhoneModelName: Lumia 520