Cut and pasted from a previous post of mine, which means the "SEARCH" function could have helped you. May not be EXACTLY what you're looking for, but should give you the place to start.
Ok, here goes:
If you're just using a xover cable (same thing as a system link cable, btw) then you need to provide STATIC IP addresses to the two computers (one being the XBOX).
I believe the flashbios defaults to what you've already mentioned.
Sooooooo Next you need to go into the network configuration of the PC. I'm going to assume you're running Windows XP.
Start -> Settings -> Network Connections
(if it's not there, go to the control panel and pic network connections there)
In Network connections, right click the Local Area Connection, or whatever name it might be, and pick Properties.
From there dbl-click on "Internet Protocol (TCP/IP)"
Next click on the dot beside Use the following IP address.
Then enter the following info:
IP Address: 192.168.0.100
Subnet Mask: 255.255.255.0
Default Gateway: 192.168.0.1 (doesn't actually matter, for this purpose.)
DNS Servers don't need to be specified either, but if you really want to put numbers in them, just put 192.168.0.100 and 192.168.0.99
OK all the way out, and they should be able to talk to each other now.
Open a Web browser, and go to
http://192.168.0.99/
The rest SHOULD be obvious.
PS: if the computer Normally is used for internet. Make a note of what the settings were before you change them and change them back afterwards or you'll likely be screwed for access. Probably "Obtain an IP address automatically".
Hope this helps. Lemme know.