Contains the delayed auto-start setting of an auto-start service.


  BOOL fDelayedAutostart;



If this member is TRUE, the service is started after other auto-start services are started plus a short delay. Otherwise, the service is started during system boot.

This setting is ignored unless the service is an auto-start service.


Any service can be marked as a delayed auto-start service; however, this setting has no effect unless the service is an auto-start service. The change takes effect the next time the system is started.

The service control manager (SCM) supports delayed auto-start services to improve system performance at boot time without affecting the user experience. The SCM makes a list of delayed auto-start services during boot and starts them one at a time after the delay has passed, honoring dependencies. There is no specific time guarantee as to when the service will be started. To minimize the impact on the user, the ServiceMain thread for the service is started with THREAD_PRIORITY_LOWEST. Threads that are started by the ServiceMain thread should also be run at a low priority. After the service has reported that it has entered the SERVICE_RUNNING state, the priority of the ServiceMain thread is raised to THREAD_PRIORITY_NORMAL.

A delayed auto-start service cannot be a member of a load ordering group. It can depend on another auto-start service. An auto-start service can depend on a delayed auto-start service, but this is not generally desirable as the SCM must start the dependent delayed auto-start service at boot.

If a delayed auto-start service is demand-started using the StartService function shortly after boot, the system starts the service on demand instead of delaying its start further. If this situation is likely to occur on a regular basis, the service should not be marked as a delayed auto-start service.

If a client calls a delayed auto-start service before it is loaded, the call fails. Therefore, clients should be prepared to either retry the call or demand start the service.


Requirement Value
Minimum supported client Windows Vista [desktop apps only]
Minimum supported server Windows Server 2008 [desktop apps only]
Header winsvc.h (include Windows.h)

See also