In Windows NT operating systems, a Windows service is a computer program that operates
in the background.
It is similar in concept to a Unix daemon.
A Windows service must conform to the interface rules and protocols of the Service Control
Manager, the component responsible for managing Windows services.
Windows services can be configured to start when the operating system is started and run
in the background as long as Windows is running.
Alternatively, they can be started manually or by an event.
Windows NT operating systems include numerous services which run in context of three user
accounts: System, Network Service and Local Service.
These Windows components are often associated with Host Process for Windows Services.
Because Windows services operate in the context of their own dedicated user accounts, they
can operate when a user is not logged on.
Prior to Windows Vista, services installed as an "interactive service" could interact
with Windows desktop and show a graphical user interface.
In Windows Vista, however, interactive services are deprecated and may not operate properly,
as a result of Windows Service hardening.
Administration Windows administrators can manage services
via: The Services snap-in
Sc.exe Windows PowerShell
Services snap-in The Services snap-in, built upon Microsoft
Management Console, can connect to the local computer or a remote computer on the network,
enabling users to: view a list of installed services along with
service name, descriptions and configuration start, stop, pause or restart services
specify service parameters when applicable change the startup type.
Acceptable startup types include: Automatic: The service starts at system logon.
Automatic: The service starts a short while after the system has finished starting up.
This option was introduced in Windows Vista in an attempt to reduce the boot-to-desktop
time.
However, not all services support delayed start.
Manual: The service starts only when explicitly summoned.
Disabled: The service is disabled.
It will not run.
change the user account context in which the service operates
configure recovery actions that should be taken if a service fails
inspect service dependencies, discovering which services or device drivers depend on
a given service or upon which services or device drivers a given service depends
export the list of services as a text file or as a CSV file
Sc.exe The command-line peer of the Services snap-in
is sc.exe, the "Service Control" utility.
This utility is included with Windows XP and later.
Sc.exe's scope of management is restricted to the local computer.
However, starting with Windows Server 2003, not only can sc.exe do all that the Services
snap-in does, but it can also install and uninstall services.
Windows PowerShell Windows PowerShell can intrinsically manage
Windows services via the following cmdlets: Get-Service
New-Service Restart-Service
Resume-Service Set-Service
Start-Service Stop-Service
Suspend-Service Other management tools
In addition to the trio of snap-in, sc.exe and PowerShell, Windows also includes components
that can do a subset of what the trio can do.
net.exe can start, stop, pause or resume a Windows service.
In Windows Vista and later, Windows Task Manager can show a list of installed services and
start or stop them.
MSConfig can enable or disable Windows services.
Development A Windows service is created using development
tools such as Microsoft Visual Studio or Embarcadero Delphi.
In order to be a Windows service, a program needs to be written in such a way that it
can handle start, stop, and pause messages from the Service Control Manager.
Service Control Manager is a component of Windows which is responsible for starting
and stopping services.
The Windows Resource Kit for Windows NT 3.51, Windows NT 4.0 and Windows 2000 provides tools
to control the use and registration of services: srvany.exe acts as a service wrapper to handle
the interface expected of a service and allow any executable or script to be configured
as a service.
sc.exe allows new services to be installed, started, stopped and uninstalled.
See also Windows services
List of Microsoft Windows components § Services Windows Service Hardening
svchost.exe Concept
Background process Daemon
DOS Protected Mode Services Terminate and stay resident program
Device driver
Operating system service management FireDaemon
Service Control Manager Service Management Facility
Service wrapper References
Further reading Savill, John.
"What are the ErrorControl, Start and Type values under the Services subkeys?".
Windows IT Pro.
Penton Media.
Retrieved 29 March 2013.
David B. Probert, Windows Service Processes