How you can turnoff the DNS lookups for the local computer. This will reduce a small amount of much-needed bandwidth and makes DNS lookups a little quicker by not resending the same dns client data. There is also the great saving of CPU time and services.exe 3,000 k memory cut down it all helps.
· Go to the Windows Control Panel double click “Administrative Tools.” icon it’s the one with the blue hammer.
· Double click on "Services" icon it’s the one with the two cog wheels
· The service panel will open then double click on the "DNS Client" service to get to the Resolves and caches Domain Name System (DNS) names.
· The DNS Client properties (local computer) panel will open then find the Start-up type pull down set it to "Disabled".
· Click on the "Stop" button once.
· Last click "OK"


DNS Disable dynamic update.

Find the Internet protocol TCP/IP properties click on advanced on the DNS tad “uncheck register this connection adders” Last thing click "OK"
Or you can go into the registry find the key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters\Interface and change the value of 1

Disable TCP clients.
This is mostly used for the limitation of concurrent TCP clients but you can set this to zero “0” so there is none. Apply a bind-9 tcp-client sub statement.
Options {
directory “/var/yourname”;
tcp-clients 0;
};
This will now disable the TCP queries and zone transfers for forwarding. But most queries are by default User Datagram Protocol (UDP) based.
If you just wanted to limit the traffic TCP clients to 200 you would neter4 this bind-9 tcp-client sub statement.
Options {
directory “/var/yourname”;
tcp-clients 200;
};

I recommend that only the true DNS servers should have the cache DNS information enabled. But Microsoft enabled this by default but this was done before DNS poisoning, pharming was a big problem with the evil attackers.

If you with to delete all the DNS resolver cache to speed up Web browsing go to the command prompt and then type “ipconfig /flushdns”. This will flush out the old addresses that have been looked up recently.

How to Enabling or Disabling DNS Lookup.

To disabled DNS lookups resolution, - Router (config) #no ip domain-lookup
To enable resolution DNS lookups - Router (config) #ip domain-lookup
Warnings with doing theses changers to the global configuration mode you will loss the DNS requests/responses in the IP packets, prevents a router from doing the name lookups.

For more good information on How to Disable Client-Side DNS Caching please see support.microsoft.com