Removing or installing an expansion card
The computer has two PCI Express x1 expansion slots, one PCI Express x16 expansion slot, and one PCI Express x16 expansion slot that is downshifted to a x4 slot.
NOTE: You can install a PCI Express x1, x8, or x16 expansion card in the PCI Express x16 slot.
For dual graphics card configurations, the first (primary) card must be installed in the PCI Express x16 slot that is NOT downshifted to a x4.
To remove, replace, or add an expansion card:
1.Remove/disengage any security devices that prohibit opening the computer.
2.Remove all removable media, such as compact discs or USB flash drives, from the computer.
3.Turn off the computer properly through the operating system, then turn off any external devices.
4.Disconnect the power cord from the power outlet and disconnect any external devices.
CAUTION: Regardless of the
5.Remove the computer access panel.
6.Release the slot cover retention latch that secures the slot covers by lifting the tab on the latch and rotating the latch to the open position.
7.Locate the correct vacant expansion socket on the system board and the corresponding expansion slot on the back of the computer chassis.
8.Before installing an expansion card, remove the expansion slot cover or the existing expansion card.
NOTE: Before removing an installed expansion card, disconnect any cables that may be 
attached to the expansion card.
a.If you are installing an expansion card in a vacant socket, you must slide one of the expansion slot covers up and out of the chassis or use a flatblade screwdriver to pry out
14 Chapter 2 Hardware upgrades