With the arrival of .Net, creation of a windows service has become a piece of cake by just selecting Windows Service as project type in the New Project Dialog Box. For installing a service, .Net provides a utility called installutil.exe which installs the service and registers it with Service Control Manager(SCM) but at times there is a need to install the service programmatically for example as a part of your custom installer program where you don't want your user to manually install the service using installutil.

The following piece of code shows how to install/uninstall a given service and register it with SCM calling appropriate APIs using P/Invoke in C#

SERVICEINSTALLER.CS

using System;
using System.Runtime.InteropServices;
namespace SvcInstaller
{
/// <summary>
/// Summary description for ServiceInstaller.
/// </summary>
class ServiceInstaller
{
#region Private Variables
private string _servicePath;
private string _serviceName;
private string _serviceDisplayName;
#endregion Private Variables
#region DLLImport
[DllImport("advapi32.dll")]
public static extern IntPtr OpenSCManager(string lpMachineName,string lpSCDB, int scParameter);
[DllImport("Advapi32.dll")]
public static extern IntPtr CreateService(IntPtr SC_HANDLE,string lpSvcName,string lpDisplayName,
int dwDesiredAccess,int dwServiceType,int dwStartType,int dwErrorControl,string lpPathName,
string lpLoadOrderGroup,int lpdwTagId,string lpDependencies,string lpServiceStartName,string lpPassword);
[DllImport("advapi32.dll")]
public static extern void CloseServiceHandle(IntPtr SCHANDLE);
[DllImport("advapi32.dll")]
public static extern int StartService(IntPtr SVHANDLE,int dwNumServiceArgs,string lpServiceArgVectors);
[DllImport("advapi32.dll",SetLastError=true)]
public static extern IntPtr OpenService(IntPtr SCHANDLE,string lpSvcName,int dwNumServiceArgs);
[DllImport("advapi32.dll")]
public static extern int DeleteService(IntPtr SVHANDLE);
[DllImport("kernel32.dll")]
public static extern int GetLastError();
#endregion DLLImport
/// <summary>
/// The main entry point for the application.
/// </summary>
#region Main method + testing code
[STAThread]
static void Main(string[] args)
{
// TODO: Add code to start application here
#region Testing
// Testing --------------
string svcPath;
string svcName;
string svcDispName;
//path to the service that you want to install
svcPath = @"C:\build\service\Debug\Service.exe";
svcDispName="Service Display Name";
svcName= "Service Name";
ServiceInstaller c = new ServiceInstaller();
c.InstallService(svcPath, svcName, svcDispName);
Console.Read();
Testing --------------
#endregion Testing
}
#endregion Main method + testing code - Commented
/// <summary>
/// This method installs and runs the service in the service control manager.
/// </summary>
/// <param name="svcPath">The complete path of the service.</param>
/// <param name="svcName">Name of the service.</param>
/// <param name="svcDispName">Display name of the service.</param>
/// <returns>True if the process went thro successfully. False if there was any
error.</returns>
public bool InstallService(string svcPath, string svcName, string svcDispName)
{
#region Constants declaration.
int SC_MANAGER_CREATE_SERVICE = 0x0002;
int SERVICE_WIN32_OWN_PROCESS = 0x00000010;
//int SERVICE_DEMAND_START = 0x00000003;
int SERVICE_ERROR_NORMAL = 0x00000001;
int STANDARD_RIGHTS_REQUIRED = 0xF0000;
int SERVICE_QUERY_CONFIG = 0x0001;
int SERVICE_CHANGE_CONFIG = 0x0002;
int SERVICE_QUERY_STATUS = 0x0004;
int SERVICE_ENUMERATE_DEPENDENTS = 0x0008;
int SERVICE_START =0x0010;
int SERVICE_STOP =0x0020;
int SERVICE_PAUSE_CONTINUE =0x0040;
int SERVICE_INTERROGATE =0x0080;
int SERVICE_USER_DEFINED_CONTROL =0x0100;
int SERVICE_ALL_ACCESS = (STANDARD_RIGHTS_REQUIRED |
SERVICE_QUERY_CONFIG |
SERVICE_CHANGE_CONFIG |
SERVICE_QUERY_STATUS |
SERVICE_ENUMERATE_DEPENDENTS |
SERVICE_START |
SERVICE_STOP |
SERVICE_PAUSE_CONTINUE |
SERVICE_INTERROGATE |
SERVICE_USER_DEFINED_CONTROL);
int SERVICE_AUTO_START = 0x00000002;
#endregion Constants declaration.
try
{
IntPtr sc_handle = OpenSCManager(null,null,SC_MANAGER_CREATE_SERVICE);
if (sc_handle.ToInt32() != 0)
{
IntPtr sv_handle = CreateService(sc_handle,svcName,svcDispName,SERVICE_ALL_ACCESS,SERVICE_WIN32_OWN_PROCESS, SERVICE_AUTO_START,SERVICE_ERROR_NORMAL,svcPath,null,0,null,null,null);
if(sv_handle.ToInt32() ==0)
{
CloseServiceHandle(sc_handle);
return false;
}
else
{
//now trying to start the service
int i = StartService(sv_handle,0,null);
// If the value i is zero, then there was an error starting the service.
// note: error may arise if the service is already running or some other problem.
if(i==0)
{
//Console.WriteLine("Couldnt start service");
return false;
}
//Console.WriteLine("Success");
CloseServiceHandle(sc_handle);
return true;
}
}
else
//Console.WriteLine("SCM not opened successfully");
return false;
}
catch(Exception e)
{
throw e;
}
}
/// <summary>
/// This method uninstalls the service from the service conrol manager.
/// </summary>
/// <param name="svcName">Name of the service to uninstall.</param>
public bool UnInstallService(string svcName)
{
int GENERIC_WRITE = 0x40000000;
IntPtr sc_hndl = OpenSCManager(null,null,GENERIC_WRITE);
if(sc_hndl.ToInt32() !=0)
{
int DELETE = 0x10000;
IntPtr svc_hndl = OpenService(sc_hndl,svcName,DELETE);
//Console.WriteLine(svc_hndl.ToInt32());
if(svc_hndl.ToInt32() !=0)
{
int i = DeleteService(svc_hndl);
if (i != 0)
{
CloseServiceHandle(sc_hndl);
return true;
}
else
{
CloseServiceHandle(sc_hndl);
return false;
}
}
else
return false;
}
else
return false;
}
}
}

The above code shows that installing a service programmatically is as simple if not simpler than using installutil and gives you far more flexibility.