Are you on a Novell Network? And in the Network Connections in the Control Panel, Double click your adapter....
Do you see this poresent? If so, and not aon a Novell Network, highlight it and uninstall....
NWLink IPX/SPX/NetBIOS Compatible Transport Protocol
And you will probably need to reset your Network Settings.....
Start>run>CMD.exe
netsh int ip reset reset.log
netsh firewall reset
netsh winsock reset