What are you supposed to do when your broadband provider's DNS servers are foobarred? First, at the very least you need to know the IP of another DNS server you can point to; great one to try is OpenDNS For instance: standard cable modem - router running dhcp on the lan side. For some reason dns queries don't work, do an nslookup, queries time-out. In Windows: Since you're typically using dhcp client it's a PINA to change this via the ncpa gui, so do it through netsh.
eth0 = the name of my interface. Since most of you are lazy and don't name your connections (like a *nix admin would), your's is probably "Local Area Connection".
netsh int ip set dns eth0 static 184.108.40.206
and where the IP is a DNS server.