Setting you DNS server addresses  
     
  On your computer:
Open Control Panel (This can be found my Start - Settings - Control Panel on most setups)
Open "Network Connections"
Right click the "Local Area Network Connection" or which ever network connection you are using to connect with us.
Click "properties"
In the white window, double click "Internet Protocol TCP/IP"
Towards the bottom there is a place for two DNS server addresses. They need to be:

172.16.248.12
172.16.248.13