mrloupcity:
Does your router have switch (lan ports mainly 10/100BaseT)?
Did you make any management settings on your router first before you get connected on your "work" computer?

Try to find if network card on your´s wife computer is fine (in way as bitwisexor has explained you).

I don´t think there can could any problems due to ME system.

You can try to share your inet connectivity through XP system on your computer. (it´s easy to try) But disadvantage is that your computer have to be always switch on to keep connectivity for your wife.

So the best solution is to make it through ethernet cable directly to router. Than it is enought to set up your wife comp "mask, DHCP server and your IP addres (in this case you will make lan network).

For example, I have at home dsl router+switch all in one (4x10/100BaseT ports) so that we have been able to make own network and share internet connectivity from one place (and it´s cheaper :) )

After connecting ethernet cable to switch of router you have to set up TCP/IP settings on your wifes computer (network settings, TCP protocol)

my router has IP address 10.0.138
it will be also your dns address and gateway on wife´s comp
than you have set up IP address on wife´s comp staticly or by DHCP server (some routers have a problems to obtain it by DHCP)
we have in our network for example 10.0.0.1 (2,3, and so on)

set your mask on 255.255.255.0

option IP/DNS/WINS set up automatically (in this case it have to be ip address of router)

Come back and tell us what you try so maybe we can help you more (maybe :) )

Hope it will work for you.