HOW TO

Use safe mode to start up and find problems

1 START UP IN SAFE MODE To start your Mac in safe mode, restart or turn it on and immediately hold the Up Arrow key until the Apple logo appears, then a login window. (Try a wired keyboard if necessary.) Release the Up Arrow key and log in to the Finder.

2 CHECK AND RESTART You can run Disk Utility from here, or check your kexts in Terminal (see above). Restart normally. If you still get the problem, restart in safe mode and go to your user account in System Preferences > Users & Groups.

3 EXCLUDE LOGIN ITEMS On the Login Items tab, make a note of the items, then select each and click – to remove it. Restart. If it’s fixed, you can add back login items one at a time by clicking + and selecting the associated app, after updating it.