If you recently upgraded your computer to Windows 10 from Windows 7 Professional, you may notice that you have to select Ctrl + Alt + Del keys to be allowed to login. This is a legacy feature left over from previous Windows version and can be disabled.
Right click on the start button and select Run
Type netplwiz and click ok
In the dialog window, select the Advanced tab and uncheck the checkbox
This will eliminate the need to use Ctrl+Alt+Del to open your machine. To reveal the login screen, just click your mouse button instead.