How do i connect two computers in a home network? one is upstais and the other downstairs?

I have one computer downstairs and another one upstairs. The computer downstairs is connected to the internet via a DSL modem by USB. Both the computers have Ethernet and USB 2.0 ports. What I want to do is to connect the two computers in some way so that both computers will have internet access. The problem is that I don't want to connect them by the means of wireless. I perfer cable. What equipment should I buy? The distance between the two computers is about 50 feet.

How do i connect two computers in a home network? one is upstais and the other downstairs?anti virus protection

You need a router. if you don't want a wireless router, then you can get a wired router and buy enough cat5 cable to run from the upstairs computer to the router downstairs. You will then connect your DSL modem to the router and both computers to the router. Go to your computer name settings from the properties of my computer and enter a workgroup name for both of them (the default is "workgroup" and will work fine also), not the domain setting. The router software should set up a dynamic host table to give both of the computers their own IP addy to communicate on so you can use automatically detect in the TCP/IP settings. the DSL modem will now recognize the DSL modem as the IP address for your home account, not that of the computer. If you want sharing permissions for files and folders then you will need to create profiles on each of the computers that give the necessary permissions for the other computers profile/sign on.