How to troubleshoot the following message in Windows XP: "A network cable is unplugged"

This article describes how to troubleshoot the following message in Microsoft Windows XP:You may receive this message when you use a network cable to connect to a local area network (LAN) or to the Internet.

This message generally appears after you lose a network signal. You may lose a network signal for several reasons. Use the following options to determine the cause of this issue:

• The network cable is loose or unplugged. To resolve this issue, verify that the network cable is plugged in securely to the correct locations on the computer and on the network device.
  
  Note Some computers may have multiple network adapters. If you are not sure where to connect the network cable on the computer, see the computer documentation, or contact the computer manufacturer.
• The network cable is defective or damaged. Examine the cable for breaks, for tears in the outer covering, or for damaged connectors. Test the network connection by using a network cable that works. If another network cable resolves the issue, replace the defective network cable.
• The network cable is plugged in securely at both ends, but the network device may not be turned on. Verify that all network hardware is plugged in to a power supply if it is required and is turned on. To resolve this issue, you may have to reset the network device. Some network devices have a reset button. Other network devices require that you turn off the power, wait for several minutes, and then turn the power back on. For more information about how to reset the network device, see its documentation.
• The network connection may be universal serial bus (USB)-based and may be plugged into a USB hub. Issues can occur on some USB hubs because of power constraints. Non-powered and congested hubs may not supply sufficient power. To resolve this issue, connect the network device directly into the USB port on the computer.
• The network cable may be the wrong type of cable. For example, a crossover cable does not function correctly as a regular network cable. To resolve this issue, replace the network cable with a network cable that works.
• The network cable is not connected to the correct port on the network device. To resolve this issue, verify that the network cable is connected to the correct port on the network device. You may lose the network signal if you connect the cable to the uplink port on a hub, on a switch, or on a router instead of on a regular port. If you are not sure where to connect the network cable, see the hardware documentation.
• Some hubs, switches, and routers disable the port next to the uplink port when the uplink port is being used. To resolve this issue, verify that the port next to the uplink port is empty. If you cannot locate the uplink port, see the hardware documentation.
• If the network adapter supports a power management option, the following check box may be selected:
  Allow the computer to turn off this device to save power
  If the network adapter supports this option, it is available on the Power Management tab of the network adapter properties dialog box. To resolve this issue, disable this option on the Power Management tab. For more information about how to disable this power management option, click the following article number to view the article in the Microsoft Knowledge Base:
  811595  (http://support.microsoft.com/kb/811595/ ) "A network cable has been unplugged" message appears at seemingly random intervals
• The value for the Media Type property on the network adapter may be set to Auto Select. This property is located on the Advanced tab of the network adapter properties dialog box. To resolve this issue, change the value of the Media Type property to a specific bandwidth. For example, set the value to 10Mbps/Full Duplex, to 100Mbps/Full Duplex, or to an optimum value.
  
  Note The steps to change this property vary depending on the manufacturer of the network adapter. In most scenarios, you can follow these steps to change the value of the Media Type property:
  1. Click Start, click Run, type ncpa.cpl, and then click OK.
  2. Right-click Local Area Connection, and then click Properties.
  3. On the General tab, click Configure.
  4. In the resulting dialog box, click the Advanced tab.
  5. In the Property list, click Media Type or Link Speed & Duplex or something similar.
     
     Note If these properties do not appear, look for a property that has the values Duplex and Half-Duplex.
  6. Click a specific bandwidth in the Value list, and then click OK.
  7. Close the Network Connections dialog box.
  8. Test the network connection.
  9. If these steps do not resolve the issue, repeat steps 1 through 5, and then click a different value in step 6 until you have tested all values.
• If you are using a PCI network adapter, the issue may relate to resources. To resolve this issue, physically move the network adapter to an adjacent PCI slot, and then restart the computer. After you restart the computer, the New Hardware Wizard detects and installs the network adapter. If you do not know how to install the network adapter, contact the computer manufacturer, or see the network adapter documentation.

For more information about other related network issues, click the following article numbers to view the articles in the Microsoft Knowledge Base: