Simply use ICS, "internet connection sharing." You need to enable ICS on the computer that is connected to the internet. This computer will need 2 NICs or "network interface cards." If your on a home network, you would connect a cable from the second NIC to your router. If your other computer is stand alone, you can use a utp Ethernet crossover cable to directly connect the 2 computers. Again, the computer connected to the internet must have 2 NICs. The other must have a single NIC.