You would hardwire the pc outback into the router, I assume, with the cable included with the router. Then you would need a NIC for the upstairs computer and the downstairs one. If price is a concern, you *could* try a USB adapter, and if the two computers aren't being used at the same time you could pull the USB adapter and take it to whichever computer you wanted. This would save buying another NIC. Even if it connects at 802.11a speeds of 11Mbps, it's still faster than cable or DSL connection, and WAY faster than dialup