I recently found a small annoyance with my iMac in that I wanted to lock my Mac whilst I was away from it and/or not using it whilst keeping all my programs running in the background. This is of course great for keeping things like Mail downloading whilst your away, which keeps things running smoothly during the day.
Let’s start by pulling up the system preferences:
We should have course have this:
Select ‘Security’ from the Personal row, which is the sixth icon. You should now be in the ‘Security’ preference panel. Continue forth to make sure the checkboxes to the left of ‘Require password to wake this computer from sleep or screen saver’ and ‘Disable automatic login’ are checked. It should look a little something like this:
Hit the ‘view all’ button in the top left of the panel to go back to the system preferences panel and continue into the ‘Desktop & Screen Saver’ preferences panel which is also located on the Personal row of preferences, this time being the third icon in. Once it’s open click ‘Screen saver’ at the top to make sure your in the right area.
Click ‘Hot Corners’ in the bottom left, this will bring up a nice drop down sub-preferences panel. Continue forth to select a corner and select ‘Start Screen Saver’ (I’ve selected the bottom left for mine).
Once this is activated if you move your mouse into the furthest point of your selected corner the screen saver should start up. Wait a few seconds (sometimes up to ten or so) and then move your mouse to bring your Mac out of it’s screen saver mode. You should then see a password prompt for your username and password – this would mean it’s worked.
No-one can now get onto your computer unless they know your username and password to get into your account.
If you would like to expand upon this and remove the screen saver from the screen after a certain amount of minutes. Go back into your system preferences panel and select ‘Energy Saver’ which is on the Hardware row – the fourth icon.
Change your slider to whatever amount of minutes you want your display to turn off on. This will remove the screen saver from your display but keep your computer running.
Make sure ‘put computer to sleep when it is inactive for’ is set to ‘Never’ and ‘Put the hard disk(s) to sleep when possible’ is unchecked. This makes sure your computer won’t stop processing applications and activity in the background whilst you are away from the computer.