In order to construct a LEGO computer tower case, you will need 6 bricks: 2 1x2 smooths with the dot in the center, 2 1x2 thins, 1 1x1 chunky, and 1 1x1 with a hole in the middle. First, take both of your 1x2s and stick them on top of the 1x1s. You'll want the hole facing outwards on the side. Next take your other 1x1 and snap that on top. Now take the 1x2 with the dot in the center and attach that to the front. Then take your remaining 1x2 with the dot in the middle and connect it into the hole in the bottom. Now you have a complete LEGO computer tower case.