Safe Mode is a powerful tool that can help resolve software and hardware issues that are often difficult to identify while a full-blown Windows installation is running.
In a nutshell, booting a machine into Safe Mode typically loads only the operating system kernel plus just a few basic hardware device drivers.
This is basically a stripped down version of the operating system that isn’t affected by any auto-loading programs or advanced device drivers.
Windows users have been booting their PCs into Safe Mode to help them track down and solve system issues for years, but many Mac users don’t realize they can take advantage of Safe Mode as well.
As with Windows, it’s very easy to boot your Mac into Safe Mode. Just follow these simple steps:
1 – If your Mac is currently running, shut it down and then turn it back on.
2 – Immediately press and hold the Shift key.
3 – Release the Shift key when the Login window appears. Your Mac should continue booting up into Safe Mode with just the bare essentials running.
(Note: You might be prompted to enter your login password).
Now that your Mac is running in Safe Mode you can troubleshoot whatever issue(s) the system is experiencing.
When you are finished with your troubleshooting session you can exit Safe Mode by simply restarting your Mac in the usual manner (i.e. without pressing any keys).
Bonus tip: This post explains how to keep malware off your Mac.