if you're running a modem, a self test should be includet. run that to make sure right drivers.
2nd hit in "run" <CMD>, and there type <IPCONFIG /ALL>
your own IP should be displayed, if not your settings are not right.
if yes, type your ip like < PING 192.168.1.17>
if you get a respond, your modem works. if not -> running firewall ???
open all ports (or allow all) and try that ping once more.
ciao