Wired Network: Speed and Duplex Settings for Windows XP
Click the Start button and select Control Panel.
Double-click the Network Connections icon.
Right-click Local Area Connection and select Properties.
Click the Configure button.
Select the Advanced tab.
In the Property box, select Speed & Duplex.
Note: The name of the property is dependent upon the type of network card you have. It may be labeled something like Media Type or Duplex.
If none of these properties are listed, select each property one at a time and check to see which options are available under the Value drop-down menu. Select the property option for which there are the value options of "full" and "half."
Click the Value drop-down menu and select Auto. Click OK.