Your computer has two horizontal drive bays and one vertical mounting position to hold up to three drives, as shown below.

Using the Correct Drive Bay

Your computer may have come with a hard disk drive already installed in the vertical mounting position. If not, you can install one 31/2-inch hard disk drive in this position.

If you are installing your first hard disk drive, it is best to install it in the vertical mounting position. If you add a second hard disk drive or diskette drive, use the lower horizontal drive bay.

7-2 Installing and Removing Disk Drives