Windows 10
1) Click Start icon (1) in the bottom left corner
2) Type about your pc (2)
3) Click on the first result, which should be About your PC (3)
4) Your computer name will be displayed under the Windows 10 logo.
Mac
1) Click the Apple icon (1) in the top left, then click on System Preferences (2)
2) Click on the Sharing icon
3) The machine name will be where it says Computer Name