I'd concentrate on the Network Adapter. Go Control Panel, System, Hardware, Device Manager and see if the Network Adapter is missing or present and yellow flagged.
If present and shown as faulty, try uninstalling it in Device Manager and then restart Windows. Windows may simply reinstall the driver and solve it -- or it may seek a driver for the Adapter and you might have to direct the Wizard to the Windows Folder and the System and System32 folders.