How can I disable a service via Delphi?

Question

I use a routine that can start and stop services via Delphi but I also need to be able to disable them, is it possible?

Answer 1

You really only need to set the appropriate registry key for the service. The start type is determined by the "Start" keyword in service configuration section of the registry:

HKLM\System\CurrentControlSet\services\YOUR_SVC_NAME\

You'll notice a REG_DWORD called Start. To set this service's startup type to Disabled, change the value of the Start key to 0x4.

Other valid options for the Start key are:

     Boot        0x0
     System      0x1
     Automatic   0X2
     Manual      0x3
     Disabled    0x4

Here's a function to get you started. Note that I have not tested this function, but it should work as-is. You will need to include the Registry unit in your uses clause like this:

uses
   Registry;

// [.........]

function SetSvcStartup(iStartType: integer): Boolean;
var
  Reg: TRegistry;
  Path: string;
begin

  //    Boot        0x0
  //    System      0x1
  //    Automatic   0x2
  //    Manual      0x3
  //    Disabled    0x4

  Reg := TRegistry.Create;
  try
    with Reg do
    begin
      RootKey := HKEY_LOCAL_MACHINE;
      Path := 'System\CurrentControlSet\services\YOUR_SVC_NAME';

      if KeyExists(Path) then
      begin
        OpenKey(Path, True);
        WriteInteger('Start', iStartType);
      end;
    end;
  finally
    Reg.CloseKey;
    Reg.Free;
  end;
end;

To set a service's startup type to "disabled", you call the function like this:

SetSvcStartup(4);

Answer 2

ShellExecute(0, nil, 'cmd.exe', 'sc config "the service name" start=disabled', nil, SW_HIDE);
ShellExecute(0, nil, 'cmd.exe', 'sc config "the service name" start=auto', nil, SW_HIDE);
ShellExecute(0, nil, 'cmd.exe', 'sc config "the service name" start=demand', nil, SW_HIDE);

Answer 3

Open the service with OpenService, and then disable it by passing Service_Disabled as the dwStartType parameter for ChangeServiceConfig. Specify a null pointer or Service_No_Change for the rest of the parameters since you're not interested in changing them.

Answer 4

This is what i use

It's just a little wrapper around some Windows API Functions we found useful to handle NT-Services. It allows you to query, start, stop, pause and enable/disable NT-Services on the local or a remote system.

http://blog.marcduerst.com/post/How-to-use-TServiceManager-to-manage-Windows-services.aspx

Which lets you write 'nice' delphi code ;)

procedure DisableService(ServiceName: PChar);
var SM: TServiceManager;
begin
  SM:=TServiceManager.Create;
   try
     SM.Connect;
     SM.OpenServiceConnection(ServiceName);

   //not working with TServiceManager as is
   //but its easy to fix, see below        
    SM.DisableService;


   finally
    SM.Free;
   end;
end;

the DisableService section hasnt been written, but all that is needed is

 procedure TServiceManager.DisableService;
 begin
   ChangeServiceConfig(ServiceHandle, SERVICE_NO_CHANGE,SERVICE_DISABLED,SERVICE_NO_CHANGE, nil, nil, nil, nil, nil, nil, nil);
 end;

Answer 5

Besides using the previous methods, if you need more control you can use WMI.
With Win32_Service class have access to all information of the services installed on the machine and you can has access to methods: Start, Stop, Pause, Resume, Interrogate, Create, Delete, Change, ChangeStartMode...

Here (Web / SourceForge)you can find a set of components to work with WMI (GLibWMI components Library); There are one called CServiceInfo thah give you all information and some methods of this class.

In addition with the package tere are some demos; One is called (ServiceControl) and implement all methods.

All the package are source included. See the code it can be usefull for you.

Regards.

Answer 6

You can use file JclSvcCtrl.pas from JEDI Components Library (JCL). I have written a pseudo example that you could use. However, be aware that I didn't test it. But in this way it should work (error checks omitted):

M := TJclSCManager.Create;
For i := 0 to M.Count -1 do
begin
  S := M.Services[i]; //TJclNtService
  if CompareText(S.ServiceName, 'bla') then
  begin
    S.Stop;
    S.StartType := sstDisabled;   
    break;
  end;
end;