Getting rid of my windows server 2003 domain controller

Hi Saad,

FYI Inplace upgrade is not supported.
1. Install new Windows 2012R2 or Windows 2016 (recommended) server.
2. promote the server to DC
https://redmondmag.com/articles/2015/03/01/active-directory-domains.aspx
3. Wait for couple of days and move FSMO roles.
https://blogs.technet.microsoft.com/canitpro/2015/02/10/step-by-step-migrating-windows-server-2003-fsmo-roles-to-windows-server-2012-r2/ 
4. Change the DNS IP in DHCP scope to the new server IP.
4. Shutdown old (2003) FSMO holder server for couple of days.
5. If everything works as expected start 2003 server and demote the server.
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2003/cc740017(v=ws.10)?redirectedfrom=MSDN 
If that is successful change the IP of 2012 server to old server 2003 to avoid any issue (for servers/PCs/network devices with static NIC configured)

Now you can install 2 more servers and demote other 2003 servers.

Thanks
MAS

In addition to the above, completely decommission the 2003 boxes and move them to a MINIMUM of 2016, preferably 2019.  You can migrate your DNS scopes easily as well to the new 2016/19 boxes.

Regards
Alex

@Mas

The Problem when i wanted to promote the Windows Server 2019 to a neu Dc in existing domain , i had an error message tht i have to raise the forset funktional level to 2008 , when i went to the windows server 2008 and and tried to raise the  forest functional level I got error that it is not doeable becaus i have 3 windows server 2003 domain controller in my domain .

what can i do ?

You must remove your 2003 domain controllers before you can update the Domain Functional Level and Forest functional level to 2008.

You can't install a 2016 box until it's at 2008, then you also need to run a forest prep and domain prep before you install the 2016 DC. Also you'll have to move from FRS to DFSR for SYSVOL replication.

Regards
Alex

You can install 2016 DC as long as you are running with windows server 2003 Domain and forest functional level

Check your both functional levels and raise them on 2003 minimum and then install 2016 server as member and promote it to DC

Once you done that, gradually decommission 2003, 2008 DC servers, after that raise functioanl level to minimum 2008 R2 or all the way to 2016 and then migrate FRS to DFSR

I was thinking of 2019, sorry.

You still need to do your FRS to DFSR change, 2016 does NOT support FRS at all anymore (since 2017 I think it was)

Regards
Alex