How to repair disk permissions in OS X

If you find  your Mac is running a bit more sluggish than usual, or a program you  frequently use starts behaving oddly, you might need to repair your disk  permissions. Please

Open the Disk Utility by selecting Applications -> Utilities -> and then Disk Utility

Select your primary hard drive (the one that you loaded OS X on) and then click the Verify Disk Permissions button

Disk Utility  will check your drive for any permission errors. In the example  screenshot below there are none (I run this program a couple of times a  month)

You may find a screen full of errors. If any errors do appear, click the Repair Disk Permissions button.