Home page
Articles for Windows, Linux, OS X
Mac tips and articles
Mac tips
Windows 8 tips and articles
Windows 7 tips and articles
Vista Tips
XP Tips
Linux tips and articles
Read the blog
Online store
Windows, Linux, OS X programs

Start in safe mode to solve problems on the Mac

Is your Mac running smoothly and error free? It probably is, but occasionally problems do occur and the computer might become unstable or even crash because of disk corruption, bad software and other reasons.

Although your Mac may be fine today, you need to know what steps you can take if disaster strikes at some time in the future and the Mac won't work properly. Safe mode can be used to fix problems with OS X and it is worth getting to know.

There are several different ways to start Apple Macs and normal mode is the one that is, er, normally used. However, there are also special modes that can be used to fix faults, such as safe mode. It's sometimes called safe boot too.

To start the Mac in safe mode you turn it on as normal, but then after a couple of seconds you hold down the Shift key. You need to do this before OS X starts loading. The Mac will start up, but much more slowly than it usually does. This is normal for safe mode because some of the optimisations normally used are skipped.

One of the things that safe mode does is to move all the font caches to the Trash that are stored in the Library folder in case they are corrupt (they are automatically rebuilt). Another task performed is to delete the dynamic loader cache, which can also cause problems if it is corrupt (again it will automatically be rebuilt). A directory check of the boot disk is performed too.

These tasks alone can solve some problems, but in case you need to perform additional tasks OS X starts with only those kernel extensions that are necessary, only Apple-installed startup items (not those you've installed yourself), and without any startup and login items.

It's basically a clean boot that loads only the bare essentials. This does mean that not every program will run, such as DVD player, video capture and so on, but other repair tools should be OK.

Related articles
* Lion: Use the Recovery Disk to fix faults
* Back up Lion's recovery partition
* Paragon's Rescue Kit for Mac OS X is free
* Diagnose problems with Activity Monitor
* Restart after a crash!
* Check your Mac's disk drive for errors
* Use the console to solve problems
* Lion's secret Wi-Fi Diagnostics