[GUIDE] Go back to Android 9 after installing android 10

[dicamarques]

First of, if you are counting on restoring from a cloud backup, it's not possible.
Because the phone looks for updates and forces you to update if you turn on wifi or mobile data!
Make sure you removed your google account from the device while on android 10!
Go to settings, accounts and remove every account you have there.

https://forum.xda-developers.com/nokia-7-plus/how-to/ota-nokia-7-plus-ota-links-t3818774
From this post, get the following files:

• 00WW 354H July 2019 Full ROM
• 00WW 354H SP01 August 2019
• 00WW 354H SP02 September 2019
• 00WW 354H SP03 October 2019
• 00WW 354H SP04 November 2019

After that, flash the last Android 9 version (Full Rom) from July.
(You might want to use this program for the full rom flash: https://forum.xda-developers.com/no...ol-stock-rom-flash-tool-nokia-7-plus-t4023961 )
Then flash August, September, October and November.

Start your device, configure it, without connecting to network. That means, you wont be able to restore from a cloud backup!

After configuring, go to developer options and disable automatic system updates!

And you're good to go.
If you ever find your device updating to android 10, change slot in fast boot.

 

[sahapurforever]

How to Downgrade 10 to 9 .
Please help me !

 

[Angry_Droid]

I just got my bootloader unlocked and want to downgrade my phone from 10 to 9. I got the files mentioned above and Nokia Tool. When I use it, it comes up with this.

getversions..
'fastboot' is not recognized as an internal or external command,
operable program or batch file.
device-info..
'fastboot' is not recognized as an internal or external command,
operable program or batch file.
Flashing abl_a..
Flashing abl_b..
Flashing xbl_a..
Flashing xbl_b..
Flashing bluetooth_a..
Flashing boot_a..
Flashing cda_a..
Flashing cmnlib_a..
Flashing cmnlib64_a..
Flashing devcfg_a..
Flashing dsp_a..
Flashing hidden_a..
Flashing hyp_a..
Flashing keymaster_a..
Flashing mdtp_a..
Flashing mdtpsecapp_a..
Flashing modem_a..
Flashing nvdef_a..
Flashing pmic_a..
Flashing rpm_a..
Flashing splash_a..
Flashing system_a..
Flashing systeminfo_a..
Flshing tz_a.
Flashing vendor_a..
Erase ssd..
Erase misc..
Erase sti..
Erase ddr..
Erase securefs..
Erase box..
Erase boot_b..
set active slot A..
Erase Userdata..
Rebooting system..

Am I missing something? Other things I should know or do?

 

[dicamarques]

I just got my bootloader unlocked and want to downgrade my phone from 10 to 9. I got the files mentioned above and Nokia Tool. When I use it, it comes up with this.

getversions..
'fastboot' is not recognized as an internal or external command,
operable program or batch file.
device-info..
'fastboot' is not recognized as an internal or external command,
operable program or batch file.

You're missing adb and fastboot, download and install https://forum.xda-developers.com/showthread.php?t=2317790