Sorry these are so big....I wanted to be able to see the details. I believe the pci-e slot is the black slot above the 2 white pci slots? I don't know what it is that is already there. On the bottom in one of the pci slots there is a card that is attached to 2 phone jack slots on the back of the computer that say "LINK" and "POWER." The top "card" in the small black slot is connected to two red and green lights on the back of the computer that say "LINK" and "PWR". I think the new graphics card should go above this in the pci-e slot, but there is not room for it to fit. What are these cards already there?