Since the recent attached on DNS servers from criminals your best bet today is to use OpenDNS.
To do this do the following:
Go to Start -> Control Panel -> Network and Internet and click Network Sharing Center
Under task listed on the left click Manage Network Connections. In Manage Network Connections right click the icon representing your network card -> click properties and in the properties list click Internet Protocol Version 4. Click Properties button in the ensuing screen and select Use the following DNS server address button. Type in a primary address of 208.67.222.222 in the secondary address type 208.67.220.220 and click Ok.
