Most computers do not start on the Tails USB stick automatically but you can press a Boot Menu key to display a list of possible devices to start from.
If Windows 8 or 10 is <span class="linux upgrade-linux">also</span> installed on the computer, you can refer instead to the [[instructions on starting Tails from Windows 8 or 10|doc/first_steps/start/pc#windows-restart]].Starting Tails from Windows is easier than using the Boot Menu key.
If the computer starts on another operating system or returns an error message, shut down the computer again and repeat step 3 for all the possible Boot Menu keys identified in step 2.