Objective
Demote and retire a domain controller without losing critical roles, DNS, Global Catalog coverage, or replication by checking Active Directory health first and validating DNS and metadata after removal.
- Protect emergency access and avoid broad permission changes that can lock out administrators or expose privileged credentials.
- Replication, Kerberos and policy changes can have delayed effects; validate on a pilot scope before broad enforcement.
- Record the current state before making a production change and keep a tested rollback path.
- Change one variable at a time. Preserve timestamps, logs and configuration evidence so the result can be explained afterward.
- Use a pilot scope whenever possible and avoid broad service restarts, policy relaxations or destructive cleanup as a first diagnostic step.
Prerequisites
- Known domain topology, administrative boundaries and privileged access method.
- Current DNS, time synchronization and replication health for identity-related procedures.
- Administrative access appropriate to the system being changed or diagnosed.
- A clearly identified scope: affected users, systems, addresses, services and the time of the observed problem.
- A maintenance or test window when the procedure can affect production traffic or availability.
- A copy of the current configuration or other recovery material before any irreversible action.
Step-by-step procedure
Establish the baseline and scope
Before changing anything, reproduce the issue or document the requested change on a representative system. Record the affected users or services, exact time, current configuration, recent changes and a known-good comparison point. This baseline is the reference used to decide whether each later step improves the situation.
- The scope and current state are documented well enough to reproduce or verify the procedure.
Active Directory health first
Work through this operational element in a controlled sequence: Active Directory health first. Record the current state, verify dependencies, perform the smallest necessary action, and validate its effect before continuing. If the result differs from the expected state, stop and reassess rather than stacking additional changes.
- Evidence for this area is explicit, reproducible and consistent with the intended design.
DNS
Work through this operational element in a controlled sequence: DNS. Record the current state, verify dependencies, perform the smallest necessary action, and validate its effect before continuing. If the result differs from the expected state, stop and reassess rather than stacking additional changes.
- Evidence for this area is explicit, reproducible and consistent with the intended design.
Metadata after removal
Work through this operational element in a controlled sequence: metadata after removal. Record the current state, verify dependencies, perform the smallest necessary action, and validate its effect before continuing. If the result differs from the expected state, stop and reassess rather than stacking additional changes.
- Evidence for this area is explicit, reproducible and consistent with the intended design.
Active Directory
Work through this operational element in a controlled sequence: Active Directory. Record the current state, verify dependencies, perform the smallest necessary action, and validate its effect before continuing. If the result differs from the expected state, stop and reassess rather than stacking additional changes.
- Evidence for this area is explicit, reproducible and consistent with the intended design.
Validate the complete service
Repeat the original user, system or application workflow from the real source and verify the complete result, not only one command or one local check. Confirm that logs and monitoring show the expected behavior and that no temporary debug, bypass, test account, rule or maintenance setting remains enabled.
- The end-to-end service works or the remaining failure is isolated to a clearly identified component.
Technical commands from the original procedure
These technical blocks are preserved byte-for-byte from the historical procedure and kept in their original order. Review names, addresses, paths and parameters before use.
Technical block 1
repadmin /replsummaryTechnical block 2
dcdiag /e /c /vTechnical block 3
netdom query fsmoTechnical block 4
Get-ADDomainController -Filter * | Select-Object HostName,Site,IsGlobalCatalog,IPv4AddressTechnical block 5
Get-WindowsFeature DNS,AD-Domain-ServicesTechnical block 6
Get-SmbShareTechnical block 7
Get-Service | Where-Object Status -eq "Running" | Sort-Object NameTechnical block 8
Uninstall-ADDSDomainController -WhatIfTechnical block 9
Uninstall-ADDSDomainController -LocalAdministratorPassword (Read-Host -Prompt "Mot de passe administrateur local" -AsSecureString)Technical block 10
Get-ADDomainController -Filter * | Select-Object HostName,SiteTechnical block 11
repadmin /replsummaryTechnical block 12
Resolve-DnsName -Type SRV _ldap._tcp.dc._msdcs.contoso.localTechnical block 13
Uninstall-WindowsFeature AD-Domain-Services -IncludeManagementToolsValidation
The procedure is validated when:
- The original symptom or change request has been tested end to end.
- The effective configuration matches the intended design and no unexplained error remains in the relevant logs.
- Temporary troubleshooting controls have been removed and monitoring remains normal.
- The result, evidence and any follow-up action are documented.
Rollback
- Restore the configuration, policy, binding, route, credential assignment or service state recorded in the baseline when the change does not meet its success criteria.
- Remove temporary rules, test objects and diagnostic settings that were introduced only for the procedure.
- After rollback, repeat the minimum health checks to confirm that the previous service level has been restored.
Troubleshooting / common errors
- Identity failures often combine DNS, time, replication, permissions and cached credentials; test each layer separately.
- When policy is involved, verify the effective user/computer context rather than only the configured object.
- If the result changes between tests, compare source, destination, identity, time and policy context before changing additional settings.
- If a command succeeds but the application still fails, continue at the next protocol or application layer instead of widening access.
- If the expected evidence is missing, verify that logging, auditing and the test path actually cover the failing component.
- If the change does not improve the measured symptom, restore the previous state and reassess the working hypothesis.
Official and vendor references preserved from the original procedure
- https://learn.microsoft.com/en-us/windows-server/identity/ad-ds/deploy/demoting-domain-controllers-and-domains--level-200-
- https://learn.microsoft.com/en-us/powershell/module/addsdeployment/uninstall-addsdomaincontroller?view=windowsserver2025-ps
Adapt names, addresses, paths and parameters to your environment. Back up the configuration and test on a limited scope first.