7.If you are not installing a new expansion card, install an expansion slot cover to close the open slot.
CAUTION: After removing an expansion card, you must replace it with a new card or expansion slot cover for proper cooling of internal components during operation.
8.To install a new expansion card, hold the card just above the expansion socket on the system board then move the card toward the rear of the chassis (1) so that the bracket on the card is aligned with the open slot on the rear of the chassis. Press the card straight down into the expansion socket on the system board (2).
Figure 7-11 Installing an Expansion Card
NOTE: When installing an expansion card, press firmly on the card so that the whole connector seats properly in the expansion card slot.