One reason AOD won't work is it only works with AMD chipset, that board has a Nvidia chipset (nforce 430). As far as winsat I have a feeling if you have a look through here, What's your memory assessment speed?
it is probably about where it should be.
Being a Nvidia based board it also uses the Nvidia drivers for the onboard ethernet. I would start with have a look in Programs and Features for the Nvidia entry and run the uninstaller. It will pop up a dialogue box asking if you want to uninstall all Nvidia drivers, or only selected ones. What you are looking for should be called something like "Network Management Tools", it is Nvidia's program for its won hardware/software firewall (among other things) and usually more trouble than it is worth. It also isn't needed at all (I never installed on any Nvidia based motherboard I had), so if it is there uninstall just that and see if that fixes the LAN problem. You could also try updating the driver using the one from Realtek as it uses the Realtek RTL8201N chip for it.
If that doesn't fix it it might be easier and cheaper to pick up a cheap NIC card, disable the onboard NIC and use the card.