Make sure your Ethernet cable is good. Try a different port on your router. If your motherboard has wireless, use one or the other, not both.
It will be hard to suggest anything else without knowing the full specs of your system. Please elaborate.
Asus M59A7 motherboard
8gb Corsair Vengeance 1600MHz
Phenom ii 965 black edition at stock, a little nervous too overclock lol
Western Digital Caviar Blue 500gb, 7200rpm
ASUS DRW-24B1ST DVD drive
Corsair cx600 PSU
That is every component in my system, I am using an ethernet cable and have no plan on using wireless any time soon.