Wilson said:
I have a newbie question.
What are permissions and why is it good to repair it after a update to the OS?
I have no idea what permissions are
Thanks.
Some people exaggerate the importance of repairing permissions, but doing it once in a while is a good idea. Before and after every update is definitely more than is necessary. First let me give you an explanation (don't worry, I didn't know what they were at first either):
Unix (the core of OS X) uses a complex set of "permissions" for every file which basically specify what users have what privileges for this file. For example, the administrator might have read, write, and execute privileges; anyone else, however, might only be allowed to execute.
It sounds odd that these could cause problems, but the system is so complex and there are so many different files that sometimes incorrect permissions can cause serious glitches.
I recommend repairing permissions about once a month. To do this, go to /Applications/Utilites. In your Utilities folder, find the program "Disk Utility." Launch it and select your hard drive on the left. Then click "Repair Disk Permissions." Let this run, and you're done! It's that easy.