There are three ways to turn Narrator on or off:
In the Windows 10 Creators Update, press Windows logo key + Ctrl + Enter on your keyboard. In previous versions of Windows 10, press Windows logo key + Enter.
On the sign-in screen, select the Ease of Access button in the lower-right corner and choose Narrator.
Go to Settings > Ease of Access > Narrator, and then move the slider under Narrator.