Connect Two Computers

For the family or small business, having your computers connected can be a great way to share data, resources, and more. This article will show you how to connect two computers using various operating systems. Note: these instructions create a private network of only two devices. For an expanded understanding of the private network concept, visit Set-up-a-Private-Network after reading this article.



  1. Plug in an ethernet cable. To connect two computers that don't have access to a shared network, you can use an Ethernet cable to make a direct connection between the two computer's Ethernet ports.
    • Some computers require a special cable called "crossover cable." This is a specialized cable that is wired in reverse. Ethernet ports have both inputs and outputs, and the crossover cable is switched so that the output from one computer connects to the input of the other.
    • Many current computers do not need a crossover cable: they use Auto-Medium Dependent Interface Crossover (Auto-MDIX), and will automatically configure the Ethernet port.
    • Most Macintosh computers built recently do not need a crossover cable.
    • If you're not sure, check your documentation to see what your system needs. If that's not available, just use a crossover cable: an auto-sensing Ethernet port will work with a crossover cable just as well as with a standard cable.
    • A crossover cable is also known as twisted pair ethernet cable.

Windows Vista, 7, or 8

  1. Connect the two computers using a crossover cable. At least one of the computers being connected should be using Windows Vista, 7, or 8.
  2. Open the Network and Sharing Center. If you're connecting a Windows 7 and Windows Vista computer together, use Windows 7 to perform these tasks.
    • Click the Start button, and then click Control Panel. In the search box, type "network," and then click on Network and Sharing Center.
  3. Select your network. In the network map, shown at the top of the Network and Sharing Center, double click on the Unidentified network icon.
    • If you have more than a single network, the icon will be named Multiple networks.
  4. Enable network discovery. If network discovery and file sharing are turned off, in Network, click the info bar containing this message: Network discovery and file sharing are turned off. Network computers and devices are not visible. Click to change..., and then click Turn on network discovery and file sharing. If you're asked for an admin password or confirmation, type the password or provide confirmation, as required.
    • Note: if one of the computers is running Windows XP, it may take a while for it to appear in the Network window. You may need to configure the XP computer as described below.

Windows XP

  1. Open the Control Panel. From the Start menu, select Control Panel or Settings, and then Control Panel.
  2. Double-click System, and then select the Computer Name tab. Enter the name of each computer and the name of the workgroup
    • The name of each computer should be unique, but the workgroup name must be identical for both.
  3. Set up the network connection. From the Control Panel, double-click Network Connections, and then connect the computer using the crossover cable.
    • If either machine's status is shown as "Disconnected", the cable is either not firmly seated or bad.
  4. Enable file sharing. Right-click the icon for the network connection, and then select Properties. Click the Advanced tab, and then click Windows Firewall Settings.
    • In the Windows Firewall Settings window, click the Exceptions tab, and make sure that Printer and File Sharing is selected.
    • It may take some time for the computer to obtain IP addresses and appear in the Network Connections window.
    • Note: if you're connecting two Windows XP computers, you'll need to do the above steps for both computers.

Macintosh OS X

  1. Hook them up. Connect an Ethernet cable from the Ethernet computer on one port to the Ethernet computer on the other.
    • If you don't have an Ethernet port, you can also use a USB-to-Ethernet adapter.
  2. Set network preferences. On each computer, in the Network preferences panel, select Show Network Port Configurations and make sure Built-in Ethernet is checked.
    • If Ethernet is active, it will be shown in the Network Status pane of the Network System Preferences panel.
  3. Enable Sharing. Open the Sharing preferences panel on one of the machines, and activate Personal File Sharing. Make note of the computer address, shown here as "afp://" (afp stands for Apple File Protocol).
  4. Set up the second computer.
    • Using a Finder window in OS X 10.3 or later, click the Network icon in the side bar.
    • When all have loaded, look for the name of the first computer you set up, and click on it.
    • You may be asked for your password.
    • Another dialog will appear with all the available volumes. Select one or all of them, and their icons will appear in your sidebar as partitions.

Using a Macintosh Computer as a Server

  1. Share computers as servers. The advantage to this is that the drive icons of the other computer will show up on the Desktop as volumes.
  2. Select "Connect to Server" from the Go menu.
    • A dialog will appear with a list of favorite servers. If your target machine's IP address does not appear in the list, click Browse or type the IP address of the target machine into the Server Address field.
  3. Click Connect. A password dialog will appear. Enter that information as required.
    • A dialog will appear, showing the volume selections on the target Mac. Once the icons appear on your Desktop, treat them as you would any other drive.


  • Straight Through -vs- Cross-Over: How to tell whether an ethernet cable is a straight-through or cross-over cable. Most standard ethernet cables are straight-through cables.
    • Straight through is a CAT-5, CAT-5e, or CAT-6 Ethernet Cable with the wires connected as follows:On both ends: Orange Stripe; Orange; Green Stripe; Blue; Blue Stripe; Green; Brown Stripe; Brown.
    • Cross-over is a CAT-5, CAT-5e, or CAT-6 Ethernet Cable with the wires connected as follows:On one end: Orange Stripe; Orange; Green Stripe; Blue; Blue Stripe; Green; Brown Stripe; Brown.
      On the other end: Green Stripe; Green; Orange Stripe; Blue; Blue Stripe; Orange; Brown Stripe; Brown.
    • The above conforms to TIA/EIA-568 standard. However, all that is important for a cross-over to work is for pins 1 & 2 (transmit) to switch places with pins 3 & 6 (receive) on the opposite end. For a straight through, pins should be the same on both ends.
    • Color sets (ex. Orange Strip & Orange) mark twisted pairs. Keeping pin sets on the same twisted pair (i.e. pins 1 & 2 on one color set, and pins 3 & 6 on another) allows best signal quality.
    • Note: TIA/EIA standard has not been established for CAT-7 or greater cabling.
    • For more information see: How to Make a Network Cable
  • If planning to connect 3 or more computers, hubs are less expensive, but waste bandwidth by repeating all signals out all ports. Switches allow more efficient use of bandwidth by sending packets only to the intended recipient.
  • To share your files, right click on any folder and choose Sharing to make them shared.
  • You can also do this with your printers to be able to print from one computer while the printer is connected to the other.
  • Check to see if your computer has an Ethernet Adapter in the back of the computer. Most new computers have this. You can tell by the documentation from the computer or by looking at the back of the computer. It looks like a phone jack, but larger, with 8-pins. Do not confuse this with a "modem" jack for dial-up phone service. Phone/modem jacks will have 2, 4 or 6 pins.
  • Many computers can determine if you are using a crossover or straight through cable. If you are not so lucky to have auto-sensing on at least one of the devices connected by a cable, you must use the correct type between them. Computer-to-switch/hub will require a straight through, computer-to-computer a crossover.
  • Notes on network and IP addresses. IPv4 (IP ver. 4) addresses are written like this: (four number groups separated by three dots). This is the case for all RFC-1166 compliant countries. Each number ranges from 0 to 255. This is known as "Dotted Decimal Notation" or "Dot Notation" for short. The address is divided into two portions: the network portion and the host portion.
    • Classful networks. The network and host portions are as follows: "n" represents the network portion and "x" represents the host portion.
    • Class A networks. The first number is between 1 to 126. 127 is a loop back subnet used to refer back to your NIC card). Example: (ex.
    • Class B networks. When the first number is 128 to 191. (ex.
    • Class C networks. When the first number is 192 to 223. Example: (ex.

Things You'll Need

  • Cross-over ethernet cable or a switch/hub with two standard "straight-through" Ethernet Cables. This is especially useful if you plan to add more computers later.

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Sources and Citations

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