Connect Two Home Computers for File Sharing
Methods for networking two computers
The simplest kind of home network contains exactly two computers. You can use this kind of network to share files, a printer or another peripheral device, and even an Internet connection. To connect two computers for sharing network resources, consider the options described below:

Connecting Two Computers Directly With Cable
The traditional method to network two computers involves making a cabled connection. Joining a single cable between the two systems provides a very reliable, dedicated network link. Several alternatives exist for networking two computers in this manner:

> Ethernet crossover cable
> Null modem serial cable or parallel peripheral cable
> Special-purpose USB cables

Ethernet - Of the above choices, the Ethernet method is preferred. It supports a reliable, high-speed connection with minimal configuration required. Additionally, Ethernet technology offers the most general-purpose solution, allowing networks with more than two computers to be built fairly easily later. If only one computer possesses an Ethernet adapter but the other has USB, an Ethernet crossover cable can still be used by first plugging a USB-to-Ethernet converter unit into the USB port.

> What are Ethernet crossover cables?
Definition: A crossover cable directly connects two network devices of the same type to each other over Ethernet. Ethernet crossover cables are commonly used when temporarily networking two devices in situations where a network router, switch or hub is not present.
Compared to standard Ethernet cables, the internal wiring of Ethernet crossover cables reverses the transmit and receive signals. The reversed color-coded wires can be seen through the RJ-45 connectors at each end of the cable:
> Standard cables have an idential sequence of colored wires on each end
> Crossover cables have the 1st and 3rd wires (counting from left to right) crossed, and the 2nd and 6th wires crossed
An Ethernet crossover cable will also feature the name "crossover" stamped on its packaging and wire casing.

Ethernet crossover cables should only be used for direct network connections. In particular, attempting to connect a computer to a hub with a crossover cable will prevent that network link from functioning. Home broadband routers have become an exception to this rule: modern consumer routers contain logic to automatically detect crossover cables and allow them to function with other types of Ethernet devices.

Serial and parallel cabling, called Direct Cable Connection (DCC) when using Microsoft Windows, offers lower performance but will also work. You may prefer this option if you have such cables readily available and network speed is not a concern. Serial and parallel cables are never used to network more than two computers.

Ordinary USB cables must not be used to connect two computers directly to each other. Attempting to do so can electrically damage the computers. However, special USB cables designed for direct connection exist; these can be used safely. You may prefer this option if your computers lack functional Ethernet network adapters.

To make dedicated connections with Ethernet, USB, serial or parallel cables requires
1 each computer has a functioning network interface with an external jack for the cable, and
2 the network settings on each computer are appropriately configured

One phone line or power cord cannot be used to directly connect two computers to each other for networking.

- srikanth dhanwada