Pc to xbox problem

hi all

Been having this problem for a while now, and put posts on other sites but no soloution as of yet. i am tring to simply connect my xbox to my pc i have my ethernet cable for the net plugged into the marvell yukon local area connection, an i have a 1394 net adaptor conection that says “connected” when there is nothing plugged into it ? If i plug my xbox into the net adaptor connection it does nothing. if i unplug my net connection an put the xbox into that i get a limited or no connection status ? my friend just plugs his in an it connects straight away ?? sure this is a simple fix but i have tried loads of things can someone please help !