diff -urN Python-3.4.3.orig/configure.ac Python-3.4.3/configure.ac
--- Python-3.4.3.orig/configure.ac	2015-03-10 19:54:16.269472000 +0000
+++ Python-3.4.3/configure.ac	2015-03-10 19:54:18.129848200 +0000
@@ -5016,7 +5016,7 @@
 case $host in
   *-*-mingw*)
     dnl default sys.path calculations for windows platforms
-    MODULE_GETPATH=PC/getpathp.o
+    MODULE_GETPATH=Modules/getpath.o
     ;;
 esac
 
diff -urN Python-3.4.3.orig/Include/fileutils.h Python-3.4.3/Include/fileutils.h
--- Python-3.4.3.orig/Include/fileutils.h	2015-03-10 19:54:16.551268400 +0000
+++ Python-3.4.3/Include/fileutils.h	2015-03-10 19:54:18.129848200 +0000
@@ -15,7 +15,7 @@
     const wchar_t *text,
     size_t *error_pos);
 
-#if defined(HAVE_STAT) && !defined(MS_WINDOWS)
+#if defined(HAVE_STAT) && (!defined(MS_WINDOWS) || defined(__MINGW32__))
 PyAPI_FUNC(int) _Py_wstat(
     const wchar_t* path,
     struct stat *buf);
diff -urN Python-3.4.3.orig/Modules/getpath.c Python-3.4.3/Modules/getpath.c
--- Python-3.4.3.orig/Modules/getpath.c	2015-03-10 19:54:17.192860200 +0000
+++ Python-3.4.3/Modules/getpath.c	2015-03-10 20:00:49.860494500 +0000
@@ -10,6 +10,10 @@
 #include <mach-o/dyld.h>
 #endif
 
+#ifdef MS_WINDOWS
+#include <windows.h>
+#endif
+
 /* Search in some common locations for the associated Python libraries.
  *
  * Two directories must be found, the platform independent directory
@@ -126,9 +130,17 @@
 #define LANDMARK L"os.py"
 #endif
 
+#ifdef __MINGW32__
+#define wcstok(line, delim, pointer)  wcstok(line, delim)
+#endif
+
 static wchar_t prefix[MAXPATHLEN+1];
 static wchar_t exec_prefix[MAXPATHLEN+1];
 static wchar_t progpath[MAXPATHLEN+1];
+#ifdef MS_WINDOWS
+static wchar_t dllpath[MAXPATHLEN+1];
+extern HANDLE PyWin_DLLhModule;
+#endif
 static wchar_t *module_search_path = NULL;
 
 static void
@@ -137,7 +149,7 @@
     size_t i = wcslen(dir);
     while (i > 0 && dir[i] != SEP)
         --i;
-    dir[i] = '\0';
+    dir[i] = 0;
 }
 
 static int
@@ -455,6 +479,26 @@
     return 0;
 }
 
+#ifdef MS_WINDOWS
+/* Calculates dllpath and progpath, replacing \\ with / */
+int GetWindowsModulePaths()
+{
+    int result = 0;
+    result = GetModuleFileNameW(NULL, progpath, MAXPATHLEN);
+    Py_NormalizeSepsW(progpath);
+    dllpath[0] = 0;
+#ifdef Py_ENABLE_SHARED
+    if (PyWin_DLLhModule) {
+        if((GetModuleFileNameW(PyWin_DLLhModule, dllpath, MAXPATHLEN) > 0)) {
+            result = 1;
+            Py_NormalizeSepsW(dllpath);
+        }
+    }
+#endif
+    return result;
+}
+#endif /* MS_WINDOWS */
+
 static void
 calculate_path(void)
 {
@@ -533,6 +577,10 @@
         }
     }
 #endif /* __APPLE__ */
+#ifdef MS_WINDOWS
+    else if(GetWindowsModulePaths()) {
+    }
+#endif /* MS_WINDOWS */
     else if (path) {
         while (1) {
             wchar_t *delim = wcschr(path, DELIM);
@@ -871,7 +923,45 @@
 }
 
 
-#ifdef __cplusplus
+#ifdef MS_WINDOWS
+/* Load python3.dll before loading any extension module that might refer
+   to it. That way, we can be sure that always the python3.dll corresponding
+   to this python DLL is loaded, not a python3.dll that might be on the path
+   by chance.
+   Return whether the DLL was found.
+*/
+static int python3_checked = 0;
+static HANDLE hPython3;
+int
+_Py_CheckPython3()
+{
+    wchar_t py3path[MAXPATHLEN+1];
+    wchar_t *s;
+    if (python3_checked)
+        return hPython3 != NULL;
+    python3_checked = 1;
+
+    /* If there is a python3.dll next to the python3y.dll,
+       assume this is a build tree; use that DLL */
+    wcscpy(py3path, dllpath);
+    s = wcsrchr(py3path, Py_GetSepW(py3path));
+    if (!s)
+        s = py3path;
+    else
+        s += 1;
+    wcscpy(s, L"python3.dll");
+    hPython3 = LoadLibraryExW(py3path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH);
+    if (hPython3 != NULL)
+        return 1;
+
+    /* Check sys.prefix\DLLs\python3.dll */
+    wcscpy(py3path, Py_GetPrefix());
+    wcscat(py3path, L"\\DLLs\\python3.dll");
+    hPython3 = LoadLibraryExW(py3path, NULL, LOAD_WITH_ALTERED_SEARCH_PATH);
+    return hPython3 != NULL;
 }
 #endif
 
+#ifdef __cplusplus
+}
+#endif
diff -urN Python-3.4.3.orig/Modules/posixmodule.c Python-3.4.3/Modules/posixmodule.c
--- Python-3.4.3.orig/Modules/posixmodule.c	2015-03-10 19:54:17.083661600 +0000
+++ Python-3.4.3/Modules/posixmodule.c	2015-03-10 19:54:18.145448000 +0000
@@ -1042,7 +1042,7 @@
 }
 
 /* A helper used by a number of POSIX-only functions */
-#ifndef MS_WINDOWS
+#if !defined(MS_WINDOWS) || defined(__MINGW32__)
 static int
 _parse_off_t(PyObject* arg, void* addr)
 {
@@ -3710,7 +3710,7 @@
             Py_END_ALLOW_THREADS
             /* FindNextFile sets error to ERROR_NO_MORE_FILES if
                it got to the end of the directory. */
-            if (!result && GetLastError() != ERROR_NO_MORE_FILES) {
+            if (!result && GetLastError() != 0 && GetLastError() != ERROR_NO_MORE_FILES) {
                 Py_DECREF(list);
                 list = path_error(path);
                 goto exit;
@@ -3765,7 +3765,7 @@
         Py_END_ALLOW_THREADS
         /* FindNextFile sets error to ERROR_NO_MORE_FILES if
            it got to the end of the directory. */
-        if (!result && GetLastError() != ERROR_NO_MORE_FILES) {
+        if (!result && GetLastError() != 0 && GetLastError() != ERROR_NO_MORE_FILES) {
             Py_DECREF(list);
             list = path_error(path);
             goto exit;
diff -urN a/Python/fileutils.c b/Python/fileutils.c
--- a/Python/fileutils.c	2014-10-11 14:21:34.292127100 +0100
+++ b/Python/fileutils.c	2014-10-11 14:21:37.011282600 +0100
@@ -511,7 +511,7 @@
    Not sure whether the MS_WINDOWS guards are necessary:
    perhaps for cygwin/mingw builds?
 */
-#if defined(HAVE_STAT) && !defined(MS_WINDOWS)
+#if defined(HAVE_STAT) && (!defined(MS_WINDOWS) || defined(__MINGW32__))
 
 /* Get file status. Encode the path to the locale encoding. */