Yesterday, I uninstall the MS office 2016 pro and restart the PC.
After the Win 10 PC start up , I could not find the Win10-login-screen.
Today, another PC , I also uninstall the Dreamweaver 2020 and then restart the PC,
it cannot show the WIN10-login-screen.
I had tried 1)reboot or Ctrl+Alt+Del
2) Restore back to previous point
3) dsim ,
but in vain.