On the VPN Connector Click Properties

Navigate to the Networking Tab

Double Click on "Internet Protocol Version 4 (TCP/IPv4)"

Click on the "Advanced..." button

Navigate to the DNS tab

Make sure the "Register this connection's addresses in DNS" box is checked. Then click OK at the bottom and all the other windows can be closed. If you're connected to the VPN you will be alerted the changes will not take affect until you hang up and dial again. Hang up and dial again to apply the changes. If you aren't connected to the VPN the changes will take affect when you connect.