The easiest and safest method to upgrade for free to Windows 11 (version 21H2) from Windows 10 is using Windows Update. The reason is that through Windows Update settings, you will get a notification letting you whether or not version 21H2 is compatible with your device, and you can through the installation with a few clicks knowing that all your files, most settings, and applications will migrate automatically.
The experience is similar to installing a cumulative update, but with the difference that this process will take longer to complete (about an hour) because of the download size (around 4 to 5GB) and because the process will perform a complete installation.
Although upgrading through Windows Update is a non-destructive process, it’s still recommended to create a temporary full backup before proceeding in case something goes wrong and you need to roll back or recover some files.
Upgrade to Windows 11 using Windows Update
To upgrade to Windows 11 from 10, use these steps:
Click on Update & Security.
Click on Windows Update.
Click the Check for updates button.
Click the Download and install button.
Click the Restart now button.
Once you complete the steps, Windows 11 will proceed to install automatically. (See also this video tutorial with the steps to upgrade using Windows Update.)
If you don’t see the notification, it is likely because Windows 11 is not fully compatible with your hardware and software configuration. In this case, it’s not recommended to proceed with the upgrade using other methods, such as the Installation Assistant or ISO file, because you may come across errors and problems. For example, soon after the October 5 release, Microsoft listed at least three known issues on Windows 11 that are preventing certain devices from upgrading.