Had a strange issue on a 2012R2 server recently. It is a VMWare VM. It restarted after this months MS updates. When it came back, Netlogon wouldn't start as the dependent workstation service was failing. Investigation showed that the Linkage subkey in the registry for this service was missing. This contains several values with GUIDs for the network adaptors, so we couldn't just copy from another machine. Had to recreate the key and get the correct GUIDs to recreate the values. This got Netlogon starting. However, I have now found that the Linkage key is missing from other services such as NetBT. Not sure whether the updates caused the issue, or whether something else caused it and it only became apparent when the services tried to start after the reboot. Anyone else seen this? Any idea of the cause? EDIT LanmanWorkstation, NetBT, NetBIOS, TCPIP services were all missing the Linkage subkey. Restored the SYSTEM registry hive from an earlier VEEAM backup. The subkeys were present in one control set, but not the other.