Your mac froze up all of a sudden and now it is rendered useless. It just stares back at you, not responding to keystrokes, mouse movements or just about anything you do. What do you do to fix it? Unfortunately, a force restart is pretty much the only way to go about fixing this kind of a problem. However, when your Mac does restart and behaves normally, there are things you can do to ensure that the freezing problem doesn’t occur again.
On a side note, if your Mac froze up for no reason, there is a high likelihood that it will happen again and happen pretty soon.
Applying some of the following fixes will help avoid that recurring problem.
First, try doing what are called NVRAM, PRAM and SMC resets. These are all soft hardware resets that can sometimes fix very pressing problems between your OS X and hardware communication. None of these resets will erase your personal data that you have saved on your Mac.
Next, you can try running repair disk permissions. Sometimes, what happens is that your Mac’s registry uses the wrong disk permissions which results in confusion. Some apps modify disk permissions in an undesirable manner and this can mean that your Mac becomes inaccessible sometimes, bringing your whole system to a halt. Repairing disk permissions will take you about 30 minutes at times but is an exercise that will be well worth its time, even if you are doing it just for maintenance sake rather than fixing anything.
You can also try reinstalling OS X or rolling back to an older OS X if your Mac continually presents you with the freeze problem. You can also rollback to an older OS X if your Mac is running slow all of a sudden, without no obvious reason. Besides these software fixes, you can also try upgrading the hardware on your Mac. This will of course cost you money but can bring your Mac up to speed in the current computing world, where apps and software are pretty demanding.