It's not a linux questions... but I know the guys here know a lot more than just ifconfig, therefore I decided to post it here. :-)

We are working on a pure windows network. It has an Active Directory.

We have changed the segment of the network on the DHCP server. We have already changed the dhcp configuration (server side) so that the new DNS server be the right IP, however, computers that have already requested (and be given) new segment addresses, still ask the old DNS for domain names.

What is the explanation for that? How can we solve it? (Buy! Do I hate all this intergrated BS).

What new DNS server - you mentioned changing the DHCP settings to setup a new scope for IP addresses to hand out, but not another DNS server? Check your clients too - although IP addresses can be obtained automatically along with associated DNS + Gateway settings, clients could also have manually configured DNS server settings which would over-rule those obtained dynamically (I think). Try "ipconfig /registerdns" to force all DHCP leases + DNS names to be refreshed and then "ipconfig /all" to see what DNS servers you're now accessing.

Well.... I can't do it right now, cause that happened on another location.... but if I'm not wrong, ipconfig reported the right DNS server, however when the computers were working, they would ask DNS queries to the old DNS address.

I think it's one "tight coupling"-with-Active-Directory problems.