Do you have to delete current (CS6) Illustrator preferences on Mac Os X?

Question

I have recently purchased the Adobe Illustrator CS6 program & Adobe CS6 Classroom in a Book. I am familiar with the Adobe InDesign & Adobe Photoshop programs, but I have never had to restore/delete default preferences.
I was able to locate the Adobe Illustrator Prefs- [startup drive]/Users/[username]/Library/Preferences/Adobe Illustrator CS6 Settings/en_US -yet I become confused from there. The en_US is a folder, yet the book is saying that it is a file that I'm supposed to be working with. When I click on the en_US folder, I am brought to many more files & folders, one saying "Adobe Illustrator Prefs" (which is a square icon that says "PREFS" in brown & gold).
My question is; am I supposed to copy & save the file that says "Adobe Illustrator Prefs" into another folder on my hard disk, or am I supposed to copy & save the folder "en_US" into another frolder on my hard disk?
Also, when deleting the current Illustrator preferences, do I delete the new folder I have to create, or do i delete the file that is already in my library? Is there an easier way of doing this?
Explaining in detail would be much appreciated!
Thank you very much in advance,
Alysia

Answer 1

Alysia,
I believe it makes good sense to save a copy of the whole folder with the preferences, for 4 to 6 reasons (even if some may disagree with 2) and 3), there will still be 1), 4), 5), and 6) left; actually 6) would seem to be enough in itself):
1) Preference corruption is something that occurs with a certain (low) probability, in connexion with the saving of them when you close down Illy, or while Illy is open; in other words there is (at least) one occasion where the preferences may have become corrupted every time you have closed down Illy;
2) The complexity of the combination of all the elements involved in closing down an application (Illy) is likely to increase the probability of saving errors as compared with a simple saving;
3) The probability may be quite different from user to user; discussions about this subject long ago, in the days of the fair forums (where there were two Illy forums) seemed to arrive at the conclusion that the probability, at least to a large degree is determined by the error frequency of the OS and/or hardware; this error frequency is most likely to increase with time;
4) Any corruption anywhere within the preferences may require your resetting some or all preferences;
5) You may encounter issues where it is uncertain whether the solution is your resetting some or all of the preferences, but there is only one way to find out.
6) If you save a copy of the preferences and a) never need to use it or b) need to use it because you have lost the preferences (anyway), either way there is no harm done.
You may compare the probability of successfully saving of a correct copy of the preferences with Illy closed ONCE and the probability of successfully saving of correct preferences in the complex of procedures EVERY TIME you use and close down Illy.
If you ignore 2) and 3) and presume the same probability by doing either ONCE and call that success probability P, the success probability will be P multiplied by itself as many times as the preferences are saved, also expressed as P^N (the Nth power of P), when saved N times.
The probability of getting a correct copy of the preferences is P, whereas the probability of keeping the preferences correct after using Illy N times is P^N.
With a success probability of 0.999 (failure 1:1000), and using Illy 1.000 times (about once a day for about three years), you will have 0.999 and 0.37, in other words 0.1% probability of failure by saving a copy and 63% probability of failure by using Illy; in other words, a factor of 630:1.
With a success probability of 0.9999 (failure 1:10.000), and using Illy 1.000 times (about once a day for about three years), you will have 0.9999 and 0.99, in other words 0.01% probability of failure by saving a copy and 1% probability of failure by using Illy; in other words, a factor of 100:1.
Obviously, 2) and 3) point to a higher probability of ending with correct (copy) preferences by a simple saving outside Illy ONCE than that resulting from using and closing Illy ONCE, which changes the figures in favour of saving a copy, and 3) points to a possibly increased change caused by ageing.
In any case, it hurts to lose the preferences, not least if needleesly done; this shows the strength of 6).
It should be noted that if you encounter 5), you may move the preferences rather than just deleting them, as mentioned in  Move the folder, thereby avoiding your having to sacrifice the preferences without knowing whether it is necessary; with a(n older) copy you will have two ways of recovering them.