As far as needing elevated privileges, you need to run the command window as an administrator.
Click Start
or
tap the key
and type cmd then hit Ctrl+Shift+Enter. Acknowledge the UAC confirmation and provide credentials if necessary. A
command window with elevated privileges will open.
As far as your DNS server is concerned, you do not have to use the one supplied by your ISP. Set the router's primary and secondary DNSto any known good DNS server, preferably a minimum number of hops from your IP address. Set your DHCP to pass this setting along along to the addresses it hands out or use itself as the primary DNS if that capability exits. Any requests will simply be passed upstream to the router's DNS.