X-box wont work? Im new to this, can you help?

[pop80_uk]

Hi
My friend has just bought an X-box online starter kit for his X-box, he has also bought a router and ethernet card for his Pc. He is using BT broadband.
Now am I right in thinking:
PC to Router, Router to BT connection, Router to X-box.
Now this is all set up yet he keeps getting errors messages (like missing IP's etc) when trying to connect the X-box through this set up!
Any ideas on how to fix this or a connection guide with the above.
Sorry its so vague, its all the detail he has given me at the moment.
Thanks

[Jarandco]

See here - http://www.xbox.com/en-GB/live/start/connect/router/

Plus check the router is Xbox Live compatible - http://www.xbox.com/en-GB/live/start...aq/routers.htm

[Neil]

Make sure the relevant firewall ports are open too.

[zoombini]

Should that perhaps be "BT to router", "Router to PC & router to Xbox".

A few additional questions if it does not work.

• 1) what make & model number is the router.
  
• 2) What type of modem is it, ethernet or USB ?
  
• 3) If it is ethernet, is the router plugged into it & the PC into the router, if so does the PC have internet access?
  
• 4) If the modem is USB, I take it that it's plugged into the PC & then you can plug the Xbox direct into the network card (no router needed), however is internet connection sharing installed & configured?