Models 6578, and 6579 have four expansion slots used to connect adapters to the peripheral component interconnect (PCI) bus.
Model 6269 only has 3 PCI slots and no AGP slot.
Installing an adapter in a PCI or AGP expansion slot
Remove the adapter from its static-protective package.
Install the adapter into the appropriate slot on the system board.
Install the adapter slot cover latch.
Note: If you are installing a Wake on LAN supported network adapter, attach the Wake on LAN cable that came with the adapter to the Wake on LAN connector on the system board. If you also want to take advantage of the Alert on LAN feature of the computer, you must install the network adapter in PCI slot 1.