1394 net adapter is a loopback feature for windows for your home network to pass through your network firewall. However, Your Local Area Network issue should be located with your NIC itself.
More that likely you have installed the windows update for your network interface card and have messed up the drivers since they are well known for causig issues like this since some lack backwards compatiblity for older operating systems.
If you could check what your model of network card that your laptop currently uses under Start/Settings/Control Panel/Device Manager/ Network adapters and right click it and select properties. Then click Details then under property select INF Section and under the value it should give an exact model of your card if it's not displayed in the header under General.