I have problem with Asrock G41MVS3: the internal lan not working when I connect rj45 cable.
the same when disconnected from the lan it displays that there are a nework connection. the drivers is from atheros and it's installed
Check your device manager to see if any hardware items are having issues (yellow triangle with exclamation point). If no issues, visit the ASROCK website and make sure you have all the current drivers (the DVD won't always have the most current drivers). Make sure all Windows updates have been installed.
Also, check the settings of IP V4 in your network card setup - make sure they have the proper settings (usually automatic).