how to gwet a internet connection on a downstairs computer with either modem or router?

[Rainman]

The easiest way is to use a wireless network. What kind of internet connection is on the upstairs computer(s)? If it is DSL or cable, you can usually install a wireless router, plug it into the cable or DSL modem, plug the upstairs computer into the router. You then would have to install a wireless adapter in the downstairs computer. Many newer computers have built-in wireless so you would just have to configure it.

There are lots of different wireless routers. Get one that is 802.11b/g/n or just b/g (cheaper). Make sure your computer wireless adapter is the same specification.

If the upstairs computer uses a modem and dials a phone number for the internet connection, wireless can still work, but the connection upstairs will need to be running and configured to share with computers on the house network. This method gives a slow connection speed, but I guess anything is better than nothing.