Now it's time to "open the box." That's right. Take the cover off of your PC.

Make sure the power is off and then pull all the plugs from the back of the computer, taking care to note what goes where. Once the "box" is free of the cables, you may want to lay it down on an open floor or table (as the picture above shows). There are usually several screws in the back, but some name brand cases often have interesting ways to snap open the case.

Once you get the case open, you should see a row of slots (long connectors at the bottom) along the back of the computer. There should be several open slots. The slots may look different. The shorter ones (and often white) with smaller connectors inside the actual slot are the PCI slots. The longer ones with larger connectors inside are the ISA slots. If you have a choice, you should have seleted a PCI NIC card and insert it into that slot. Next to the open slot at the back, you should see a slot cover fastened to the case with a screw. It should look like this:

Remove the screw (but keep it in a safe place...you'll use it once you get your new card in place) and the slot cover.

Now, you're ready to insert your new card. Make sure to not touch any of the electronics or soldered pins on the back. Gripping it from the edges, place it over the slot and insert it straight down. It may need a little force, but as long as you are pushing straight down, it should be fine if you need to push a bit.

Once you feel it settle into the slot, push hard on the back and front top edge to make it's seated. Insert the screw back into the back edge and tighten it down.

That's all you need to do. If you can, you might want to put the computer back and reconnect all the wires in the back while the case is still open.