Question HKEY_LOCAL_MACHINE ServiceLastKnownStatus

[BTRY B 529th FA BN]

Every computer I have is magically getting a DWORD key in the HKEY_LOCAL_MACHINE header. The Dword key is "ServiceLastKnownStatus" Value 2(2) and it never goes away. I can delete it and it reappears


What the F is that about?

 

[mikeymikec]

No idea, I don't see it on my Win10 VM; the last update installed on that was KB5060533 (June cumulative).

Does it immediately re-appear? You might be able to track it with sysinternals process monitor (filter out purely for registry accesses).

 

[pcgeek11]

The Windows registry entry ServiceLastKnownStatus provides information about the last known state of a service. It's located within the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\<ServiceName> registry key, where <ServiceName> is the name of the specific service. This entry is a DWORD value and doesn't directly control the service's behavior; instead, it reflects the service's status as recorded during the last system boot or service control operation.



Key aspects of ServiceLastKnownStatus:

• Reflects State:
  It stores the last known state of the service, such as whether it was running, stopped, or in a paused state before the system was last shut down or the service was last interacted with.
• DWORD Value:
  The value is a DWORD (32-bit integer) that represents the service's state using specific numerical codes.
• Not a Control:
  It's crucial to understand that this entry is a record of the service's state, not a setting that actively controls the service. Changes to this value will not directly affect the service's behavior.
• Location:
  The registry path is structured as: `HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\<ServiceName>\` where <ServiceName> is the name of the service you're interested in (e.g., wuauserv for Windows Update service).
• Possible Values:
  The DWORD value can hold various numerical codes representing different service states. These codes are defined by the operating system and indicate whether the service was started, stopped, paused, or in some other state. Microsoft Q&A describes how to find the state from the registry.
  

Example:
If you navigate to the registry path HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\wuauserv, you'll find the ServiceLastKnownStatus entry for the Windows Update service (wuauserv). If the value is 0x00000001, it indicates that the service was last known to be running, according to Microsoft Q&A.


In summary: The ServiceLastKnownStatus registry entry is a historical record of a service's state and should not be confused with settings that actively control the service. It's a useful piece of information for understanding past service behavior, but not for directly manipulating a service's operation.