If you have installed some apps from the Store or some Desktop apps AFTER you upgraded to a newer build of Windows 10, they will be removed. You customization preferences for local accounts won't be moved to the previous build. For Microsoft Accounts, your settings should be seamlessly migrated.
Finally, keep in mind that Windows 10 will again try to install the most recent Insider Preview build over the older build of Windows 10 that you are trying to restore. You might want to temporarily disconnect your network connection.Ensure that your user account has administrative privileges. Now, follow the instructions below.
Ensure that you have enough disk space on your C:\ drive. It is recommended that the free space on your drive be twice the size of your Windows.old folder to allow the OS to move and copy its files.
The Windows Insider program involves receiving pre-release builds of Windows 10. A huge number of users are participants of the program on different Rings. This allows them to receive very fresh versions of the operating system with new features. Often, new builds come with bugs which can make the computer unbootable or unusable. In this case, it is a good idea to go back to a previous build.
Go Back to the Previous Build in Windows 10
Go to Update & security - Recovery.
On the right, scroll to the "Get started" button under Go back to the previous version of Windows 10
After a couple of seconds, you will be asked to fill in the reason why you are removing the release. You can select one of the following reasons:
My apps or devices don't work on this build
Earlier builds seemed easier to use
Earlier builds seemed faster
Earlier builds seemed more reliable
For another reason
4. Next, you will be prompted to check for the latest updates and see if your issue can be resolved.
5. After that, Windows 10 will remind you that you need to know the password of the user account in the previously installed operating system.