Computers, Laptops & Tablets Accessories & Hardware Installing a PCI Adapater Card Add peripherals to your computer with a new PCI card by Mark Kyrnin Writer Mark Kyrnin is a former Lifewire writer and computer networking and internet expert who also specializes in computer hardware. our editorial process LinkedIn Mark Kyrnin Updated on October 20, 2020 Accessories & Hardware Cards The Quick Guide to Webcams Keyboards & Mice Monitors HDD & SSD Printers & Scanners Raspberry Pi Tweet Share Email Before you can add new hardware peripherals to your computer, you may need to upgrade the PCI adapter. Learn how to install a PCI card in your desktop PC. Westend61 / Getty Images How to Install a PCI Adapter Card Before beginning any work on the inside of your computer, it is important to make sure there is no power. Shut down the computer. Once the computer has safely shut down, flip the switch on the back of the power supply to the Off position and then remove the power cord. Open the computer. The method for opening the computer case depends on how it was manufactured. Most new cases use either a side panel or a door. Older ones require that the whole cover be removed. Remove any screws that fasten the cover to the case and set the screws aside in a safe place. Remove the PC card slot cover. Determine which slot inside the computer the PCI card will be installed in. Most cases have an internal slot cover that must be unscrewed from the case. Some cases have covers that simply snap into the slot. If you're replacing an old PCI card, disconnect any hardware peripherals before removing the card. Insert the new PCI card. Position the PCI card in the slot directly over the connector. Then gently push down on both sides of the card until it slides into place. Fasten the PCI card to the case with the screw in the slot cover. Some new cases may use a tool-free connector that snaps into place over the card cover to hold the card in place. Carefully attach any internal or external cables between the PCI card and the hardware peripherals. Close the computer case. Return the panel or cover to the case and fasten it with the screws that you previously removed. Power up the computer. Plug the AC power cord into the computer. Then flip the switch on the back of the computer to the On position. Once the system has detected the hardware, it should request any necessary device drivers. Refer to the documentation that came with the adapter card for software installation instructions.