The other day a friend of mine obtained a new hard drive which was formated for PC and he needed to use it on a Mac at school, I feebly attempted over the phone to guide him through the process of erasing and formatting the drive to use on his Mac, but he had no luck. He ended up having to come over to my house so I could format it for him and show him how it’s done.  I figured since he had some trouble figuring this out there has got to be other people who have had the same problem.
Formattinga new or used hard drive on a Mac is a little different from doing it on a PC. On a PC all you do is right click on the drive, select format and either choose the quick format, or the full which takes a little longer, very easy. On your Mac it’s a little different, but not hard at all.

1. Open up finder and go to your applications folder in your left hand sidebar.

2.  Open up your disk utility.

3. Once you have opened up disk utility, look in the left hand sidebar and select the drive you would like to format or erase, then click on the erase button.

4.  Now that you are in the erase section you will select from the Volume Format pull down menu.  After clicking on the menu it will bring up a list of option, there are only two you will need to choose from.If you will only be using this for your Mac such as for Time Machine or storing files you will only access on your Mac, then select Mac OS Extended (Case-sensitive, Journaled).  If you plan on using it with a Mac and PC, such as transferring files between the two then you will select MS-DOS  (FAT), this will give you the ability to get files off your PC and put them on your Mac or vise versa.  There is one downside to this method, it will not always transfer folders that have large file sizes from your Mac to the hard drive.  on my friends when we were taking files from my Mac to the newly formated hard drive some folders that were over 7 GB would not transfer and we had to transfer each file separately, it was kind of a pain.  We were able to transfer single files that were over 7GB with no problem, for some reason it was only the folders we had trouble with, and I could find no explanation to why, my guess would be it is some restriction from Apple.  I hope this guide helps and I will have some more cool things to use disk utility for in the future.