Inno安装 – 在文件复制前正确停止服务

[Files]
Source: "MyService.exe"; DestDir: "{app}"; Check: IsServer; BeforeInstall: BeforeServiceInstall('MyServiceName','MyService.exe'); AfterInstall: AfterServiceInstall('MyServiceName','MyService.exe')

procedure BeforeServiceInstall(SvcName,FileName: String);
var
  S: Longword;
begin
  //If service is installed,it needs to be stopped
  if ServiceExists(SvcName) then begin
    S:= SimpleQueryService(SvcName);
    if S <> SERVICE_STOPPED then begin
      SimpleStopService(SvcName,True,True);
    end;
  end;
end;

procedure AfterServiceInstall(SvcName,FileName: String);
begin
  //If service is not installed,it needs to be installed now
  if not ServiceExists(SvcName) then begin
    if SimpleCreateService(SvcName,'My Service Name',ExpandConstant('{app}')+'' + FileName,SERVICE_AUTO_START,'',False,True) then begin
      //Service successfully installed
      SimpleStartService(SvcName,True);
    end else begin
      //Service failed to install

    end;
  end;
end;

当第一次安装服务(不存在并且当前不运行)时,此服务的安装/启动工作正常.但是,在现有安装(升级)上运行此安装程序时,安装程??序在识别到此服务正在运行时停止,并提示终止进程(在调用BeforeServiceInstall()处理程序之前)…

如何防止此提示出现在服务中？我避免不必要重新启动,并且仍然希望这个提示出现在所有其他文件中.