DELETE FROM dbo.CVM_VM_MASTER_IMAGE WHERE MASTER_IMAGE_ID = 'image_id';
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Provisioning\OMADM\Accounts HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Enrollments
After restarting services, wait 5–10 minutes for lock timeouts to clear, then retry unregistration.
DELETE FROM dbo.CVM_VM_MASTER_IMAGE WHERE MASTER_IMAGE_ID = 'image_id';
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Provisioning\OMADM\Accounts HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Enrollments failedtounregistermasterimagefrommdm
After restarting services, wait 5–10 minutes for lock timeouts to clear, then retry unregistration. DELETE FROM dbo