Hello Toidi357,
I'm John an Independent Advisor and a Microsoft user like you. I'll be happy to assist you today. I understand you want to downgrade your Windows version from 20H2 to 19H2. If it has been more than 10 days then you need to back up your important files and perform a Clean Installation of Windows 10 version 1909.
Unfortunately, Microsoft no longer offer downloads for older version of Windows.
Please try to use the link below to download an older version of Windows ISO file directly from Microsoft servers.
https://tb.rg-adguard.net/public.php
Select type:
Windows (Final)
Select version:
Windows 10, Version 1909 - 19H2 (build 18363.418)
Select edition:
Windows 10
Select language:
English International
Select file:
Win10_1909_EnglishInternational_x64.iso
Please try to check this link on how to create an installation media using Rufus
https://www.tenforums.com/tutorials/2376-create...
Please change the boot order in the Bios Settings. Boot your PC from the Installation Media you just created. Please refer to the link below on how to perform a Clean Installation of Windows by Greg.
https://answers.microsoft.com/en-us/windows/for...
I hope this helps! Please let me know if you have any further concerns.
Sincerely
John DeV
Independent Advisor
Standard Disclaimer: This is a non-Microsoft websites. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.