I have steam installed in my laptop and it is annoying that steam is starting automatically when my system starts. I have unchecked the option "Run Steam when my computer runs" and disabled from startup programs in task manager as well. Is there anything else I could do to stop this?
Assuming you mean the Task Manager (if not: Ctrl+Shift+Esc 🠖 Start-up 🠖 Steam Client Bootstrapper, Right-click, 'Disable'), try disabling the Steam service:
In the Start menu, type
services, and open the Windows Services app.
In the list showing up, look for Steam Client Service, Right-click it, select Properties, and set Startup Type to 'Manual'.