DNS IP to localhost

While I am doing this coding of DNS server and using my development machine to debug the program, I need to somehow configure my Windows 7 client's DNS setting to point to itself as the DNS server (e.g. 127.0.0.1).

Surprisingly, Windows 7 rejects the setting when you put 127.0.0.1 as the DNS IP address of your network connection.

Found the following Powershell to change it easily

$wmi = Get-WmiObject win32_networkadapterconfiguration -filter "ipenabled = 'true'"
$wmi.SetDNSServerSearchOrder("127.0.0.1")