Remove an identity sensor deliberately when decommissioning its domain controller

Keep this document to one review outcome: Remove an identity sensor deliberately when decommissioning its domain controller. Only the official source and traced locations below supply facts. Confirm applicability before acting.

Source fact:

The official Remove the Microsoft Defender for Identity sensor from Microsoft supports the following bounded statements:

• Microsoft documents sensor removal for domain-controller decommissioning, orphaned or duplicate sensor cleanup, and intentionally stopping monitoring on a server. The research record locates this support at Opening applicability statement.
• Deleting a v3.x sensor removes its software and stops Defender for Identity monitoring on that domain controller. The research record locates this support at V3 deletion effect.

The source support ends with the statements listed above. Use them to examine Defender for Identity workspaces, sensors, directory-service accounts, action accounts, network paths, roles, and deployment health in the applicable environment, not to imply a wider guarantee.

What the source does not establish

Coordinate server, monitoring, retention, and incident owners before removal; deletion creates an intentional coverage gap. The citation is not a substitute for observed state, authorization, compliance evidence, or dependency health. Examine Active Directory, Windows DNS, time, certificates, domain-controller resources, network capture, cloud connectivity, and security operations before translating the source into an operational decision.

Applicability questions

• For source statement 1 at Opening applicability statement, which observable configuration, record, or test can confirm applicability here?
• For source statement 2 at V3 deletion effect, which observable configuration, record, or test can confirm applicability here?
• Which deployed instance of Defender for Identity workspaces, sensors, directory-service accounts, action accounts, network paths, roles, and deployment health will be compared with the source, and why that instance?
• How will the review distinguish a source mismatch from a failure in Active Directory, Windows DNS, time, certificates, domain-controller resources, network capture, cloud connectivity, and security operations?
• Who approves the conclusion, exception, test window, and rollback threshold?

DSE recommendation:

DSE recommends using the cited source as the evidence anchor for this decision. Make the source, asset scope, owner, and expected outcome explicit in the review record. Record the source location, examined part of Defender for Identity workspaces, sensors, directory-service accounts, action accounts, network paths, roles, and deployment health, observed and expected states, owner, and reason for deviation.

If the review warrants change, use a bounded implementation with prerequisites, test population, monitoring, abort criteria, and a rehearsed reversal. Sequence checks for Active Directory, Windows DNS, time, certificates, domain-controller resources, network capture, cloud connectivity, and security operations and sanitize protected material before retention.

Verification and evidence

Evidence should let another reviewer reproduce this decision. Retain observations beside the traced locations Opening applicability statement; V3 deletion effect. Favor sensor inventory, service and action-account permissions, health alerts, connectivity tests, portal state, and controlled detection tests, linked to stable identifiers, time, and operator.

Retain the starting state, authorization, execution record, outcome, deviation, and final state as one review package. Move disruptive checks to an approved test path. Reopen the decision when versions, design, dependencies, ownership, or official guidance changes.

Official references

• Remove the Microsoft Defender for Identity sensor — Microsoft