diff -urN a/configure.ac b/configure.ac
--- a/configure.ac	2014-10-11 14:21:34.252124800 +0100
+++ b/configure.ac	2014-10-11 14:21:37.003282200 +0100
@@ -5031,7 +5031,7 @@
 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 a/Include/fileutils.h b/Include/fileutils.h
--- a/Include/fileutils.h	2014-10-11 14:21:35.290184200 +0100
+++ b/Include/fileutils.h	2014-10-11 14:21:37.005282300 +0100
@@ -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 a/Modules/getpath.c b/Modules/getpath.c
--- a/Modules/getpath.c	2014-10-11 14:21:35.080172200 +0100
+++ b/Modules/getpath.c	2014-10-11 14:21:37.006282300 +0100
@@ -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
@@ -207,7 +219,11 @@
 joinpath(wchar_t *buffer, wchar_t *stuff)
 {
     size_t n, k;
+#ifdef MS_WINDOWS
+    if (stuff[0] == SEP || (stuff[0] != 0 && stuff[1] == L':'))
+#else
     if (stuff[0] == SEP)
+#endif
         n = 0;
     else {
         n = wcslen(buffer);
@@ -228,7 +244,11 @@
 static void
 copy_absolute(wchar_t *path, wchar_t *p, size_t pathlen)
 {
+#ifdef MS_WINDOWS
+    if (p[0] == SEP || (p[0] != 0 && p[1] == L':'))
+#else
     if (p[0] == SEP)
+#endif
         wcscpy(path, p);
     else {
         if (!_Py_wgetcwd(path, pathlen)) {
@@ -248,7 +268,11 @@
 {
     wchar_t buffer[MAXPATHLEN+1];
 
+#ifdef MS_WINDOWS
+    if (path[0] == SEP || (path[0] != 0 && path[1] == L':'))
+#else
     if (path[0] == SEP)
+#endif
         return;
     copy_absolute(buffer, path, MAXPATHLEN+1);
     wcscpy(path, buffer);
@@ -455,6 +479,35 @@
     return 0;
 }
 
+#ifdef MS_WINDOWS
+/* Calculates dllpath and progpath, replacing \\ with / */
+int GetWindowsModulePaths()
+{
+    int result = 0;
+    wchar_t* seps;
+    result = GetModuleFileNameW(NULL, progpath, MAXPATHLEN);
+    seps = wcschr(progpath, L'\\');
+    while(seps) {
+        *seps = L'/';
+        seps = wcschr(seps, L'\\');
+    }
+    dllpath[0] = 0;
+#ifdef Py_ENABLE_SHARED
+    if (PyWin_DLLhModule) {
+        if((GetModuleFileNameW(PyWin_DLLhModule, dllpath, MAXPATHLEN) > 0)) {
+            result = 1;
+            seps = wcschr(dllpath, L'\\');
+            while(seps) {
+                *seps = L'/';
+                seps = wcschr(seps, L'\\');
+            }
+        }
+    }
+#endif
+    return result;
+}
+#endif /* MS_WINDOWS */
+
 static void
 calculate_path(void)
 {
@@ -533,6 +586,10 @@
         }
     }
 #endif /* __APPLE__ */
+#ifdef MS_WINDOWS
+    else if(GetWindowsModulePaths()) {
+    }
+#endif /* MS_WINDOWS */
     else if (path) {
         while (1) {
             wchar_t *delim = wcschr(path, DELIM);
@@ -561,7 +618,11 @@
     else
         progpath[0] = '\0';
     PyMem_RawFree(path_buffer);
+#ifdef MS_WINDOWS
+    if (progpath[0] != '\0' && progpath[0] != SEP && progpath[1] != L':')
+#else
     if (progpath[0] != SEP && progpath[0] != '\0')
+#endif
         absolutize(progpath);
     wcsncpy(argv0_path, progpath, MAXPATHLEN);
     argv0_path[MAXPATHLEN] = '\0';
@@ -871,7 +932,43 @@
 }
 
 
-#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, L'\\');
+    if (!s)
+        s = py3path;
+    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 a/Modules/posixmodule.c b/Modules/posixmodule.c
--- a/Modules/posixmodule.c	2014-10-11 14:21:35.095173000 +0100
+++ b/Modules/posixmodule.c	2014-10-11 14:21:37.010282600 +0100
@@ -1019,7 +1019,7 @@
 }
 
 /* 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)
 {
@@ -3689,7 +3689,7 @@
             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;
@@ -3744,7 +3744,7 @@
         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. */