Returns a list of all services on the system.

def _get_services():
    '''
    Returns a list of all services on the system.
    '''
    handle_scm = win32service.OpenSCManager(
        None, None, win32service.SC_MANAGER_ENUMERATE_SERVICE)

    try:
        services = win32service.EnumServicesStatusEx(handle_scm)
    except AttributeError:
        services = win32service.EnumServicesStatus(handle_scm)
    finally:
        win32service.CloseServiceHandle(handle_scm)

    return services