First, there are a few ways you can determine if your PC was upgraded from Windows 10 to Windows 11:
1. Check the system information: Right-click on the Start button and select "System" from the context menu. In the System window that opens, you'll see the operating system information. If it says Windows 11, then your PC is running Windows 11. If it says Windows 10, then it was not upgraded.
2. Look at the version number: Open the Settings app by pressing Windows key + I, then go to System -> About. Under the "Windows specifications" section, you'll find the Windows version. If it says anything starting with "11", then it's Windows 11. If it says "10", then it's Windows 10.
3. Check the Windows Update history: Open the Settings app, go to Windows Update -> View update history. If you see any Windows 11 updates listed there, it's an indication that your PC was upgraded.
4. Check the upgrade notification: If you haven't dismissed the Windows 11 upgrade notification, you can hover over the Windows icon in the taskbar to see if it mentions Windows 11. If it does, then your PC was likely upgraded.
Second, if your PC was upgraded to Windows 11 and you want to revert back to Windows 10, you can follow these steps:
1. Open the Settings app by pressing Windows key + I, then go to System -> Recovery.
2. Under the "Recovery options" section, click on the "Advanced options" link.
3. In the Advanced options menu, look for the "Go back to Windows 10" option and click on the "Get started" button.
4. Follow the on-screen instructions to complete the rollback process. Keep in mind that this process is time-limited, meaning you have a specific amount of time (typically 10 days) to revert back to Windows 10 after upgrading to Windows 11.
It's worth noting that reverting back to Windows 10 will uninstall any apps or settings you've added since upgrading to Windows 11, so it's recommended to create a backup of your important files before proceeding.
I hope this helps! Let me know if you have any further questions.