This support function forces IIS to reprocess the discretionary access control list (DACL) for an ISAPI extension's DLL. Given sufficient security permissions, this support function can be used to reprocess another extension's DACL, as well.
BOOL ServerSupportFunction(
HCONN ConnID,
DWORD HSE_REQ_REFRESH_ISAPI_ACL,
LPVOID lpvBuffer,
LPDWORD lpdwSize,
LPDWORD lpdwDataType
);
Note that your extension can use this support function to force IIS to reprocess either its own DACL, or the DACL of another ISAPI DLL.