Greetings, Mohammad! My name is Arif, and I will assist you today.
Does this prompt message always show up when you restart or shut down your computer?
The prompt you’re seeing—“Someone else is still using this PC. If you shut down now, they could lose unsaved work”—is a common notification in Windows 11. Even if you're the only user, this message can appear as a precaution. You can shut down your computer safely, but if there's any unsaved work, it’s best to log in again and save it before shutting down. If you find this message annoying, you can send feedback to Microsoft by pressing the Windows key + F and suggesting an option to disable it.
Warm Regards,
Arif