Xbox live

[dannyk]

I know this is a gaming forum but hopefully someone can help me with the following:
I want to connect to xbox live using the following setup:

1 x PC
xbox
Broadband modem
RJ45 crossover cable

My PC connects to the internet via my ethernet broadband modem
My xbox connects to my PC via a network card
No matter what i cannot seem to get onto Live. My PC can see my Xbox on the network (when i pop my evox cd into the xbox & use flashfxp).
Does anyone know the settings i need..?? I have ticked &unticked everything in the connection sharing a hundred times. My xbox always comes up with DNS not found. Any help would be most gratefull.

DannyK