Here is how you ensure greater security with your installation of Windows 10. Require the use of Ctrl-Alt-Del to access the login screen.
To enable Crtl-Alt-Del
In Search Windows, enter netplwiz.
Click Run Command.
In the User Accounts dialog, click the Advanced tab.
In the Secure Sign-in panel, click the Require users to press Crtl-Alt-Delete check box.
Your good to go!
You might also want to set the Screen saver Wait time:
In Search Windows, enter Settings.
Click Lock Screen, then Screen saver settings to open the Screen Saver Settings dialog.
In the Wait text box enter a time in minutes, such as 5 or 10. I prefer 10 minutes as I don't want to have to log in again every time I check my notes or ask a colleague a question.
Ensure On resume, display logon screen is checked.
Click OK to dismiss the dialog.
So, now you should be set up to have additional level of security on your Windows 10.