homepage

To test windows callbacks, I suggest to use EnumResourceTypes() instead, which is more likely to work in any condition:
def test():
 from ctypes.wintypes import BOOL, HMODULE, LONG, LPARAM
 import ctypes
 EnumResourceTypes = ctypes.windll.kernel32.EnumResourceTypesA
 EnumResTypeProc = ctypes.WINFUNCTYPE(
 BOOL, HMODULE, LONG, LPARAM)
 resource_types = []
 def callback(hModule, typeid, lParam):
 resource_types.append(typeid)
 return True # keep enumerating
 hModule = None # Main executable
 RT_MANIFEST = 24 # from winuser.h
 EnumResourceTypes(hModule, EnumResTypeProc(callback), None)
 assert RT_MANIFEST in resource_types