Before starting the migration process, ensure you have:

• Administrative privileges on both servers
• Backup of your current Active Directory (System State backup recommended)
• Windows Server 2008 installation media or ISO
• Network connectivity between both servers

First, install Windows Server 2008 on your new hardware. Then run these commands in an elevated command prompt to prepare the forest and domain:

dcdiag /v /c /d /e /s:currentDC > dcdiag.log
repadmin /showrepl
repadmin /replsummary

These commands will verify your current AD health and replication status.

Run the following PowerShell script to install AD DS and promote the server:

Import-Module ServerManager
Add-WindowsFeature -Name AD-Domain-Services -IncludeManagementTools
Install-ADDSDomainController 
    -DomainName "yourdomain.com" 
    -InstallDNS:$true 
    -Credential (Get-Credential) 
    -DatabasePath "C:\Windows\NTDS" 
    -LogPath "C:\Windows\NTDS" 
    -SysvolPath "C:\Windows\SYSVOL" 
    -NoRebootOnCompletion:$false

After the new DC is up, transfer all Flexible Single Master Operations (FSMO) roles:

# List current FSMO holders
netdom query fsmo

# Transfer roles using ntdsutil
ntdsutil
roles
connections
connect to server newDC.yourdomain.com
q
transfer schema master
transfer naming master
transfer PDC
transfer RID master
transfer infrastructure master
q
q

Once you've verified all roles have transferred and replication is working properly, demote the old server:

dcpromo /forceremoval

After demotion, you may need to manually clean up metadata using:

ntdsutil
metadata cleanup
connections
connect to server newDC.yourdomain.com
q
select operation target
list domains
select domain 0
list sites
select site 0
list servers in site
select server oldDC
q
remove selected server
q
q

Complete these final steps:

1. Update DNS settings on all clients to point to the new DC
2. Verify Group Policy replication
3. Test authentication from multiple workstations
4. Monitor event logs for several days

For additional verification, run:

dcdiag /test:FSMOCheck /v
dcdiag /test:Advertising /v
dcdiag /test:MachineAccount /v

---

Before starting the migration process, ensure you have:

• Administrative credentials for both servers
• Network connectivity between old and new servers
• AD health check completed on the 2003 server (run 'dcdiag /v')
• System state backup of current DC
• Sufficient disk space on the new server

First, install Active Directory Domain Services role on the new server:

# PowerShell command to install AD DS
Import-Module ServerManager
Add-WindowsFeature -Name AD-Domain-Services -IncludeManagementTools

Run this on the new server to add it to the existing domain:

# Using dcpromo with answer file
dcpromo /unattend /InstallDns:yes /ConfirmGc:yes /CreateDNSDelegation:no /ReplicaOrNewDomain:replica /ReplicaDomainDNSName:yourdomain.local /UserDomain:yourdomain /UserName:administrator /Password:**** /DatabasePath:"C:\Windows\NTDS" /LogPath:"C:\Windows\NTDS" /SYSVOLPath:"C:\Windows\SYSVOL" /SafeModeAdminPassword:*****

After replication completes, transfer all FSMO roles to the new server:

# Command to transfer all roles
netdom query fsmo
# Then for each role:
ntdsutil
roles
connections
connect to server newdc.yourdomain.local
quit
transfer schema master
transfer naming master
transfer PDC
transfer RID master
transfer infrastructure master

Check the AD replication status and verify operations:

repadmin /showrepl
repadmin /replsummary
dcdiag /test:replications /v
dcdiag /test:fsmocheck /v

Once you confirm the new DC is functioning properly:

# On the old 2003 server
dcpromo /forceremoval

After demotion, clean up metadata:

# On the new 2008 DC
ntdsutil
metadata cleanup
connections
connect to server newdc.yourdomain.local
quit
select operation target
list domains
select domain 0
list sites
select site 0
list servers in site
select server olddc.yourdomain.local
quit
remove selected server

• Update DHCP to point to new DC for DNS
• Reconfigure any applications using LDAP
• Verify GPO replication
• Test user logins and group policies

If you encounter replication errors:

repadmin /syncall /A /e /q

For DNS issues:

dnscmd /clearcache