Microsoft® Certificate Server runs as a Microsoft Windows NT® service. By default, it is setup to have automatic Startup Type. Consequently, it will start automatically when the operating system loads unless the service has been reconfigured to have manual Startup Type. Additionally, The Certificate Authority service will stop automatically when the operating system is unloaded, or it can be stopped manually.
If the Certificate Authority service has been configured to have its Startup Type be manual, then the service must be started manually.
The Certificate Authority service will always stop automatically when the operating system is unloaded. It can also be stopped manually, regardless of whether it was started automatically or manually.