Thanks Jonathan it worked.
Karlsnooks, I didn't really understand you.
My computer was built from separate parts in a computer store.
Everest says that my network adapter is "Realtek RTL8168B/8111B Family PCI-E Gigabit Ethernet NIC"
I would be happy if you could find me the newest driver
, because I didn't find.. something is wierd in the "realtek.com" web site..