Why is my Steam guard not enabled?
Once you have the menu open click on Settings. If you don't have Steam Guard enabled, it means you haven't verified your contact e-mail address with Steam, or you manually disabled it.
How do I authorize Steam guard?
When Steam Guard is enabled on your account, anyone attempting to login to your Steam account from an unrecognized computer must provide additional authorization. A special access code will be sent to your contact email address, and this code must be entered into Steam before your login is complete.
How do I know if I have Steam guard?
In the "Account" tab of your Settings or Preferences menu, "Security Status" will display "Protected by Steam Guard" if Steam Guard has been enabled. Note: After enabling Steam Guard, you will need to wait 15 days before you can trade or use the Community Market.
How do I set up Steam Mobile Guard?
How do I force 1920x1080 on steam?
How do I know how long my Steam Guard has been enabled?
How do I force a game to 1080p on steam?