Password Protect All Computer Accounts

As with any online service, it's important to keep your computer account protected with a secure password. When you leave your computer or close your laptop, the password will ensure you are the only one who can regain access to its data.
 

Password Protect Windows 10 Accounts

1. Click the Start button at the bottom left of your screen.
2. Click Settings from the list to the left.
3. Click Accounts.
4. Click Sign-in options from the menu.
5. Click Change under Change your account password.
6. In order to change your password, you have to sign in with your current Microsoft account password. Enter your password in the box. Click Sign in.
7. Microsoft will send you a new code to change your password through the phone number that is associated with your account. Enter the last four digits of your phone number to verify it is the correct number. Press Enter.
8. You will receive a code on your phone. Enter the code on your computer.
9. A new page will direct you to enter your old password and then type in a new password. Reenter the new password. Press Enter.
10. You've successfully changed/set your password.
     

Password Protect Accounts on macOS 10.9+

1. From the Apple menu, click System Preferences.
2. In the System Preferences window, click the Users & Groups icon in the fourth row.
3. If the lock icon in the lower-left hand side of the window is locked, click it to unlock it.
4. Be sure your account is highlighted in the column on the left and click Change Password...
5. Enter your old password if necessary, your new password, and click Change Password.
6. At the bottom of the left-hand column, click Login Options.
7. Confirm that Automatic login is Off.
8. Click the lock in the lower-left corner of the window to prevent further changes.