The BIOS on your computer lets you enable and disable all hardware components inside the machine. For example, if you have an empty PCI card slot on your motherboard, you might want to disable that slot in the BIOS. However, if you ever install a new piece of hardware you will need to go back into the BIOS program and turn the PCI card slot back on.
Turn on your computer. Press your BIOS entry keyboard key when the words "Setup" or "BIOS" (whichever is applicable) appear on screen. The key you are required to press will be listed on screen. For example, on a Sony Vaio computer, you press either F2 or F3. On a Toshiba Satellite laptop you press F1.
Highlight the "Hardware" category of your BIOS. Press "Enter" to open the category.
Scroll down to the listing for the PCI slot on your motherboard that you want to enable. Press "Enter." Two options will appear on screen: "Enable" or "Disable."
Highlight "Enable" and press "Enter." The PCI slot on your motherboard will be enabled.
Highlight the "Save Changes and Exit" option of your BIOS. Press "Enter." The PCI card slot will remain enabled and your computer will reboot.