Ok, so I'm making a neat black ops 2 window 7 start button and I've made the .bmp and got the start button done, but when I put it on there's a black circle with the design showing the original start button. I wan't it off, transparent so it's just the design, like the Abstergo Orb from AC:

See how there's no black circle just the design? here's what mine looks like:

There's like a black circle and the design is semi-transparent... Anybody know how to fix this?