#pragma comment( lib, "advapi32.lib" )
#define UNICODE
#define _UNICODE

#include <string>
#include <iostream>

namespace std_ext {

#ifdef UNICODE

	std::wostream &tcout( std::wcout );
	std::wostream &tcerr( std::wcerr );
	std::wistream &tcin( std::wcin );

	typedef std::basic_string< wchar_t > tstring;

#elif

	std::ostream &tcout( std::cout );
	std::ostream &tcerr( std::cerr );
	std::istream &tcin( std::cin );

	typedef std::string tstring;

#endif /* UNICODE */
}

#include <windows.h>
#include <tchar.h>

namespace winapi_tools {

	std_ext::tstring get_last_error_msg( ) {

		void *message_buffer = 0;

		FormatMessage(

			FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
			0,
			GetLastError( ),
			MAKELANGID( LANG_NEUTRAL, SUBLANG_DEFAULT ),
			reinterpret_cast< LPTSTR >( &message_buffer ),
			0,
			0
			);

		std_ext::tstring error_message( reinterpret_cast< LPTSTR >( message_buffer ) );

		LocalFree( message_buffer );

		return error_message;
	}
}
int main( ) {

	SC_HANDLE service_control = OpenSCManager( 0, SERVICES_ACTIVE_DATABASE, SC_MANAGER_ENUMERATE_SERVICE );

	if( !service_control ) {

		std_ext::tcerr << _T( "Error: " ) << winapi_tools::get_last_error_msg( ) << std::endl;
		return EXIT_FAILURE;
	}

	unsigned long bytes_needed( 0 );
	unsigned long num_services( 0 );
	unsigned long resume_handle( 0 ); /* unused */

	if( !EnumServicesStatusEx( service_control, SC_ENUM_PROCESS_INFO, SERVICE_WIN32, SERVICE_ACTIVE, 0, 0, &bytes_needed, &num_services, &resume_handle, 0 ) && ( GetLastError( ) != ERROR_MORE_DATA ) ) {

		std_ext::tcerr << _T( "Error: " ) << winapi_tools::get_last_error_msg( ) << std::endl;
		return EXIT_FAILURE;
	}

	unsigned char *service_status_bytes = 0;

	try {

		service_status_bytes = new unsigned char[ bytes_needed ];

	} catch( std::bad_alloc &e ) {

		std_ext::tcerr << _T( "Not enough memory!\n" ) << std::endl;
		return EXIT_FAILURE;
	}

	if( !EnumServicesStatusEx( service_control, SC_ENUM_PROCESS_INFO, SERVICE_WIN32, SERVICE_ACTIVE, service_status_bytes, bytes_needed, &bytes_needed, &num_services, &resume_handle, 0 ) ) {

		std_ext::tcerr << _T( "Error: " ) << winapi_tools::get_last_error_msg( ) << std::endl;
		return EXIT_FAILURE;
	}

	ENUM_SERVICE_STATUS_PROCESS *service_status = reinterpret_cast< ENUM_SERVICE_STATUS_PROCESS* >( service_status_bytes );

	for( unsigned long i( 0 ); i < num_services; ++i ) {

		std_ext::tcout.width( 3 );
		std_ext::tcout.fill( _T( ' ' ) );
		std_ext::tcout << i << _T( ": " ) << service_status[ i ].lpDisplayName << _T( " (" ) << service_status[ i ].lpServiceName << _T( ")" ) << std::endl;
	}

	delete[ ] service_status;
}

greetz, Swordfish

Versuche es mal mit EnumWindows().

rofl