If you need to connect two computers but you don't have access to a network and can't set up an ad hoc network, you can use an Ethernet crossover cable to create a direct cable connection.
Generally speaking, a crossover cable is constructed by reversing ("crossing over") the order of the wires inside so that it can connect two computers directly. A crossover cable looks almost exactly like a regular Ethernet cable (a "straight-through" cable), so make sure you have a crossover cable before following these steps.
Before buying a crossover cable, check your network adapter. Some newer network adapters automatically "cross over" when they detect that they are connected directly to another network adapter using a regular Ethernet cable.
This works best if both computers are running this version of Windows.
Plug each end of the crossover cable into a network port on the back of each computer.
On one of the computers that is running this version of Windows, do the following:
Open Network and Sharing Center by clicking the Start button , clicking Control Panel, clicking Network and Internet, and then clicking Network and Sharing Center.
In the network map at the top of Network and Sharing Center, double-click the Unidentified network icon. (If you have more than one network, this icon will be labeled Multiple networks.)
If network discovery and file sharing are turned off, in Network, click the Information bar containing the following 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 are prompted for an administrator password or confirmation, type the password or provide confirmation.
In the Network discovery and file sharing dialog box, select one of the following options:
No, make the network that I am connected to a private network
Yes, turn on network discovery and file sharing for all public networks
The first option is usually the best choice because it only affects the network that you are connected to.
Networks created with crossover cables are automatically set up as "Public place" networks, which means that network discovery, file sharing, and printer sharing are off by default.
For Gigabit Ethernet or token ring networks, you will need a slightly different kind of crossover cable. For more information, contact a cable manufacturer.
Icons for both computers should now be visible in the Network window. Double-click each computer icon to share printers and other resources.
If one of the computers is running Windows XP, it can take some time for that computer to appear in the Network window. You might need to move both computers to the same workgroup. You can do that by changing the workgroup on either computer. To change a workgroup, see Join or create a workgroup. You might also need to turn on file and printer sharing on the computer running Windows XP.