I had exactly the same problem. I've spent a day trying to figure it out. Now I know and it works like a charm.
If you have several network cards and if if specify DNS server in each of them. Do you know what DNS server will be used at last?
Well you can check it via practice.
nslookup 192.168.3.6
So you see the server that your PC actually use
The question is - From what depends what DNS server windows choose to use and how we can change it.
We especially need it when we use VPN clients.
The answer from qwerty2010 is right and correct. But you can use it ONLY when you have NIC in control panel - network and sharing center - change adapter settings - list of nics
Only if you see the nic that is reponsible for your VPN client you can use graphical way to point windows what dns server (that is specified on a particular nic) you'd like to use.
So you go Network and sharing centre -> Change adapter settings -> Advanced -> Advanced settings -> and you move UP the nic with DNS you'd like to USE. (UP you need to lift it UP).
However if for instance you use Shrew vpn client - you will not have any nics.
What do you do.
You open registry.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}
And you look in subfolders 0000, 0001 etc the folder with
DriverDesc = Shrew Soft Virtual Adapter
fine. Then you copy to the clipboard
NetCfgInstanceId = {B498E7DE-7257-48F6-AD32-60E470030F05}
Now you go
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\Linkage]
and you open key = Bind
. You'll see the list like this
\Device\{1DF89CE3-CAAD-4EB7-A53F-AD16BC1D5EFD}
\Device\{70126DBE-B44D-4392-9417-0CABD6E384B1}
\Device\{D5127F8E-E7BB-4661-AE5A-A922614173D0}
\Device\{C44039AB-6801-4A9B-A736-3B12782FF411}
\Device\{85231D0F-CD05-4774-A983-632C5D83AC62}
\Device\{7E87BC81-8C58-4E05-9FA0-7897A6AA5CCE}
\Device\{3A1A3EFC-A9DE-4BCA-BAF6-81C7074487E0}
\Device\{8D41EDFC-04AC-4537-B5D5-0D54EB51A023}
All you have to do is put to the top
\Device\{B498E7DE-7257-48F6-AD32-60E470030F05}
\Device\{1DF89CE3-CAAD-4EB7-A53F-AD16BC1D5EFD}
\Device\{70126DBE-B44D-4392-9417-0CABD6E384B1}
\Device\{D5127F8E-E7BB-4661-AE5A-A922614173D0}
\Device\{C44039AB-6801-4A9B-A736-3B12782FF411}
\Device\{85231D0F-CD05-4774-A983-632C5D83AC62}
\Device\{7E87BC81-8C58-4E05-9FA0-7897A6AA5CCE}
\Device\{3A1A3EFC-A9DE-4BCA-BAF6-81C7074487E0}
\Device\{8D41EDFC-04AC-4537-B5D5-0D54EB51A023}
That's all. There is no need to reboot.
Now your windows will use DNS specified in shrew vpn nic when you use vpn connection.