god damn xbox 360!

I got my x box 360 at christmas, its now july and i STILL cant hook it up to the internet, no matter how any different cables and sockets i try it just wont work and its doin my head in. Then a few days ago i was told that you cant hook the Xbox 360 to your computer if you have your internet hooked up to a USB port instead of the ethernet cable, and if you have that then you cant do it at all.

What the hell for? is this true and if anyone else has encountered the same problem let me know if you fixed it cause im freakin out!