Yes, you are correct. Get a gold plated
Crossover cable the reason i say gold, is becuase any other plating like copper etc... will give you some interference later on in the future as you use it more and more. Ive tried all of these things. You want to connect the crossover cable to an open ethernet port in your desktop. Then im not sure if it varies, for to connect to xbox live, you need to turn off windows firewall otherwise it wont let connection through. So first try going online with the windows firewall on and if that doesnt work try turning it off and connecting and it should work. If you have further questions or are having some trouble please contact me and i will gladly help further.