I want to discard my old 2003 server and migrate to windows 2008 R2. How can I migrate with the same domain name and same DNS without change clients?

Hello Rafiq,

I think i can assist you on this, some how this process could be lengthy though migration from2003 to win2008 R2 DC will decommission the current version on the machine, 

Need to check whether your DC is used as an application servers. If not do the following tricks!

Demote the2003 Dc server first , record the existing IP address settings and remove the from that from the Domain carefully, so as remove the NS if there any associated with same Domain.

Now configure your new2008 R2 server with the same static IP and do run DC promo

while running you need to select DC options as "DNS server" "Global catalog server" this will be very useful for migration.Once it is done you will be encountering some error message leave that since it can be rectified once we run a DC promo in reboot mode.

Now you just verify the DNS Zones has been replaced. you now need WINS to be running on your side you can reconfigure it on your wish all you need is to Raise domain functional level and forest functional level to replace your domain name to the existing one.

By default recycle bin in2008 R2 is disabled you need to manually enable it.

Now you redirect all users and computers to that domain must be running on new2008 R2 server . Have a good Luck techy!