Here are different ways to close all running apps and programs on Windows 11/10 using Task Manager, Command Prompt, PowerShell, etc.

How to run startup commands on Windows Sandbox To run scripts or commands during login on Sandbox, use these steps: ...

Learn how to run Task Manager as Admin from CMD, PowerShell, Run, etc., for a Standard User too in Windows 11/10. You may need it to kill some processes.

The Windows Installer service might be an issue, but you can restart it. Type cmd in the Search bar to open Command Prompt and select Run as administrator in the right-hand menu.

You can add a work or school account to Windows, even if you're already using a local account or Microsoft account.