I'm not 100% sure I get your setup, I think you're trying to use your laptop as a wireless bridge?
My current interpretation (if this is wrong, my answer will be wrong!)
- You have a wireless router that provides your internet?
- This provides DHCP and internet over WiFi to your laptop?
- Your laptop is then connected by a ethernet cable to the XBOX?
So, it looks roughly like this:
Internet --- Router ) ) ) Laptop --- XBOX
(wireless link) (wired link)
First: could you not just connect your XBOX by cable to your router directly? I assume not, otherwise you wouldn't be messing around trying to bridge with your laptop, but this is the easiest option if it's possible.
Assuming you can't do that, you should try bridging the connections on your laptop.
To bridge your connection
- Disconnect the wired connection.
- Go in to your Network Connections screen (the one it the background for you screenshot).
- Select both the wired and wireless connections and right-click them.
- Select Bridge Connections.
- Wait, it can take a short while to create.
- Reconnect the wired connection.
See here for offical instructions, but they're effectively the same.
I would also disable ICS as well or it might get in the way.