diff --git a/twain/load_sane.cpp b/twain/load_sane.cpp
index 67901e7..3695ee7 100644
--- a/twain/load_sane.cpp
+++ b/twain/load_sane.cpp
@@ -91,20 +91,27 @@ namespace load_sane_util
 	{
 		HMODULE h = LoadLibraryW(path_dll);
 		int		ret = GetLastError();
+		wchar_t	info[128] = { 0 };
 
+		swprintf_s(info, _countof(info) - 1, L" = %d\r\n", ret);
+		OutputDebugStringW((L"[TWAIN]Load: " + std::wstring(path_dll) + info).c_str());
 		if (!h && ret == ERROR_MOD_NOT_FOUND)
 		{
 			std::wstring	dir(path_dll);
 			size_t			pos = dir.rfind(L'\\');
 			wchar_t			path[MAX_PATH] = { 0 };
 
-			GetCurrentDirectoryW(_countof(path) - 1, path);
+			GetDllDirectoryW(_countof(path) - 1, path);
 			if (pos != std::wstring::npos)
 				dir.erase(pos);
-			SetCurrentDirectoryW(dir.c_str());
+			OutputDebugStringW((L"[TWAIN]Load: try change directory to " + dir + L"\r\n").c_str());
+			SetDllDirectoryW(dir.c_str());
 			h = LoadLibraryW(path_dll);
 			ret = GetLastError();
-			SetCurrentDirectoryW(path);
+			swprintf_s(info, _countof(info) - 1, L" = %d\r\n", ret);
+			OutputDebugStringW((L"[TWAIN]Load: " + std::wstring(path_dll) + info).c_str());
+			OutputDebugStringW((L"[TWAIN]Load: restore directory to " + std::wstring(path) + L"\r\n").c_str());
+			SetDllDirectoryW(path);
 		}
 
 		if (dll)
@@ -142,6 +149,13 @@ namespace load_sane_util
 	}
 	bool is_ok(void)
 	{
+		wchar_t	info[128] = { 0 };
+		swprintf_s(info, _countof(info) - 1, L"[TWAIN]Load: sane_inst: %s, is_on: %s, init: %s, uninit: %s\r\n"
+			, sane_inst != NULL ? "ok" : "not found"
+			, is_on != NULL ? "ok" : "not found"
+			, init != NULL ? "ok" : "not found"
+			, uninit != NULL ? "ok" : "not found");
+
 		return sane_inst != NULL && is_on != NULL && init != NULL && uninit != NULL;
 	}
 	bool is_online(SCANNERID guid)