Question : DNS Server value keeps changing!!

Hi,
We have had some problems on our network since yesterday (although nothing has changed). Users have been having problems accessing mail and application servers.
When an IPCONFIG /ALL is done it looks fine and the DNS Servers are listed as 172.16.0.4 and 172.16.0.2 which is correct. When the problem occurs the IPCONFIG /ALL still looks fine but the DNS server IP changes to 192.168.1.1 which is not in our IP range.
I have checke the domain controllers etc., but cant find any reason why this is happening.
Can anyone help before I go insane??

Answer : DNS Server value keeps changing!!

Is there a chance that you have a DHCP server on the network with the same IP address?

Try to disconnect the DHCP server for 1 or 2 min and ping the IP address and see if you get reply!

Is this problem is particular to a specific computer or it is with all?

By any means, do you have the scope mis configured on DHCP server?