How to Adjust the Speed of My Local Area Connectionby Kirk Bennet
By default, your network adapter is configured to automatically negotiate the transfer speed with the device it's connected to. Local area connections usually work at a speed of 100 Mbps full duplex. In full duplex mode, the adapter can send and receive network packets at the same time. In half duplex mode, the adapter can perform a single operation at a time. In Windows 7, you can adjust the speed of your network adapter and also change the duplex settings.
Click "Start | Control Panel | Network and Internet | Network and Sharing Center."
Click the "Change adapter settings" in the left pane, and then right-click the "Local Area Connection" connection and choose "Properties" from the context menu.
Click the "Configure" button, and then click the "Advanced" tab.
Select "Speed & Duplex" in the Property list.
Select the speed and duplex settings in the Value box. Your choices are 1.0 Gbps Full Duplex, 10 Mbps Full Duplex, 10 Mbps Half Duplex, 100 Mbps Full Duplex and 100 Mbps Half Duplex. Auto Negotiation allows the network adapter to negotiate the maximum speed with the device it's connected to.
Click "OK" to apply and save the new settings.