I need to make my OS Case Insensitive.

A normal OS X filesystem is already case-insensitive so I am assuming maybe you meant case-sensitive. The only way I know to change it is to repartition and reformat the drive being sure to use Mac OS Extended, Journaled. In order to install OS X you will need the original discs that came with that model when it was new. You cannot use the retail version of Snow Leopard nor can you install Lion or later without first installing Snow Leopard. Your model came with a special version of OS X that was only supplied on the discs that came with the computer.

Clean Install of Snow Leopard

1. Boot the computer using the Snow Leopard Installer Disc or the Disc 1 that came

with your computer. Insert the disc into the optical drive and restart the computer.

After the chime press and hold down the "C" key. Release the key when you see

a small spinning gear appear below the dark gray Apple logo.

2. After the installer loads select your language and click on the Continue

button. When the menu bar appears select Disk Utility from the Utilities menu.

After DU loads select the hard drive entry from the left side list (mfgr.'s ID and drive

size.) Click on the Partition tab in the DU main window. Set the number of

partitions to one (1) from the Partitions drop down menu, click on Options button

and select GUID, click on OK, then set the format type to MacOS Extended

(Journaled, if supported), then click on the Apply button.

3. When the formatting has completed quit DU and return to the installer. Proceed

with the OS X installation and follow the directions included with the installer.

4. When the installation has completed your computer will Restart into the Setup

Assistant. After you finish Setup Assistant will complete the installation after which

you will be running a fresh install of OS X. You can now begin the update process

by opening Software Update and installing all recommended updates to bring your

installation current.

Download and install Mac OS X 10.6.8 Update Combo v1.1. You may now access the App Store in order to download your copy of Mavericks to install.

The problem you have is whatever is installed on the computer it belonged to the previous owner. You can't use it. You need to completely start from scratch. If you don't have the discs then contact Apple to purchase replacements, if available. Or contact the seller for the discs since they should have been included in the sale.

Apple Store Customer Service at 1-800-676-2775 or visit online Help for more information.

To contact product and tech support: Contacting Apple for support and service - this includes

international calling numbers..