recycled , low budget grow box

i wanted a box approx 1'x2'x4'tall but couldnt think of anything to use then it hit me. i got an old computer desk on wheels its 15" deep 40" across 28" tall , but when its flat on its side, it becomes 15"deep 28" wide and 40" high, i am going to unscrew all the inside and use it to cover the back or front and maybe get plywood to fill the rest. fits perfect in the closet. also going to recycle my old pc tower for a seed/clone/veg room.