It didn't give you an IP becuase your set to DHCP and you don't have a DHCP server... nevermind.
Set your PC to this
IP 192.168.0.10
SM 255.255.255.0
DG 192.168.0.10
Set your xbox to this
IP 192.168.0.30
SM 255.255.255.0
DG 192.168.0.30
THen go to your PC and open run command (start--->run)
type in cmd and hit enter
In the window that pops up type ping 192.168.0.30
If it answers back your fine... if not you obviously have a virus and have to reload your whole PC and sell your xbox to someone who knows what ping means.
