Preparing for end of support for CNAME auto-discovery in Windows MDM-only enrollment

What changed

From 15 January 2027, EnterpriseEnrollment CNAME discovery is no longer supported for Windows MDM-only enrollment; the enrollment service URL may need to be supplied explicitly.

Why it matters

DNS-dependent onboarding instructions can leave new MDM-only users unable to locate the enrollment service; existing enrolled devices and Entra join enrollment are not affected.

Known limitations

• Existing enrolled devices remain enrolled; Windows MDM-only enrollment itself remains supported.
• Entra join and hybrid join enrollment are not affected when they do not rely on this CNAME discovery.

Now check

• Inventory Windows MDM-only onboarding workflows that depend on EnterpriseEnrollment CNAME discovery
• Test explicit enrollment with https://enrollment.manage.microsoft.com/enrollmentserver/discovery.svc before 15 January 2027
• Update deployment, onboarding and help-desk instructions; do not remove DNS records used by other workflows without review