Problem Phenomenon：
Windows 11 has been officially released on October 5, 2021, but the update has not been pushed to all users. If your computer is currently on Windows 10 system and meets the requirements for upgrading Windows 11, it's recommended to wait for the OTA. If you want to update Windows 11 immediately, you can refer to the following method via Windows 11 installation assistant to manually update and install Windows 11.
Solution：
Note: All information and programs are retained when your computer is upgraded to Windows 11. To prevent data loss, it's recommended that you back up your data and connect your computer to a power supply.
1. Download Windows 11 Installation Assistant.
Download link：https://www.microsoft.com/en-us/software-download/windows11
2. Run Windows 11 Installation Assistant.exe program and click "Accept and Install".
3. Wait patiently for the download and installation. The user can use the system normally. The following screen will appear; no need to click, just wait patiently.
After that, it will start installing Windows 11 automatically. Meanwhile, you need to save your ongoing work since your PC will restart automatically after a specific time once it reaches 100%
If you do not want to wait and restart immediately, click the Restart now button.