Are you connected to a router? or straight to modem? to reinstall LAN, go to your hardware profiles. Right click, my computer, properties, hardware tab, device manager. Click + on your network adapter. right click the device(probably will say, 10/100 Network connection, click uninstall restart. follow the direction on your computer after restart when it says FOUND NEW HARDWARE. if Windows doesn't find the required hardware driver, make it look it up on windows or system folders!