Win32Service

Win32Service is a Windows service implemented using the Win32 API. It refers to a background process that is managed by the Service Control Manager (SCM) and is designed to run without a user interface. Windows services can start automatically at boot, start on demand, or be disabled, and they typically run under a dedicated service account.

A service is implemented as a Windows executable that exports a ServiceMain entry point. To connect to the SCM, the service uses StartServiceCtrlDispatcher, which binds the process to the SCM, and registers a control handler (via RegisterServiceCtrlHandlerEx) to receive control codes. The service communicates its status to the SCM with the SERVICE_STATUS structure and updates status using SetServiceStatus. A typical service runs one or more worker threads to perform its tasks and responds to control codes such as STOP, PAUSE, CONTINUE, and SHUTDOWN.

Installation and configuration are performed through the SCM. A service is created with either CreateService or command-line utilities such as sc.exe, and assigned a service type (for example SERVICE_WIN32_OWN_PROCESS or SERVICE_WIN32_SHARE_PROCESS) and a startup type (SERVICE_AUTO_START or SERVICE_DEMAND_START). Services can be configured with failure actions, recovery options, and security contexts. They generally run under accounts such as LocalSystem, LocalService, NetworkService, or a specific user account.

Management and troubleshooting involve starting, stopping, querying status, and configuring recovery policies via tools like Services.msc, sc.exe, or PowerShell cmdlets. Logs are typically written to the Windows Event Log to aid monitoring and diagnostics. Win32Service programs are designed to minimize user interaction, handle errors gracefully, and clean up resources during shutdown.

See also: Service Control Manager, Windows services, Win32 API, Event Log.