I bought a computer that has two network cards on it. 1) NETGEAR FA311 2) SiS 900 PCI, it is currently using the netgear card, and while it works more or less OK, its very old and won't play an online videogame very well. I've been told by the tech support team to switch to SiS card, but when I do, it does not work... how do I make this switch?

You need to enable the other network card and configure it properly so it works wit your router or ISP, I don't know what you are using

The router is a d-link di-604, 4-port ethernet broadband router... I don't know if that's what you are looking for, my isp is shaw.ca

Check the configuration of your old nic and configure the new nic equally

Why not just take the Netgear out of the PC. Then just plug your router into the other connection.