diff --git a/PC/bdist_wininst/install.c b/PC/bdist_wininst/install.c
--- a/PC/bdist_wininst/install.c
+++ b/PC/bdist_wininst/install.c
@@ -647,7 +647,6 @@
 {
     char fullpath[_MAX_PATH];
     LONG size = sizeof(fullpath);
-    char subkey_name[80];
     char buffer[260 + 12];
     HINSTANCE h;
 
@@ -657,14 +656,11 @@
     h = LoadLibrary(fname);
     if (h)
         return h;
-    wsprintf(subkey_name,
-             "SOFTWARE\\Python\\PythonCore\\%d.%d\\InstallPath",
-             py_major, py_minor);
-    if (ERROR_SUCCESS != RegQueryValue(HKEY_CURRENT_USER, subkey_name,
-                                       fullpath, &size) &&
-        ERROR_SUCCESS != RegQueryValue(HKEY_LOCAL_MACHINE, subkey_name,
-                                       fullpath, &size))
+    /* Now look in python_dir - this has come from the InstallPath in
+    // the registry (but only if our buffer is big enough!) */
+    if (strlen(python_dir)+strlen(fname)+2 >= _MAX_PATH)
         return NULL;
+    strcpy(fullpath, python_dir);
     strcat(fullpath, "\\");
     strcat(fullpath, fname);
     return LoadLibrary(fullpath);
@@ -1732,6 +1728,7 @@
 static BOOL OpenLogfile(char *dir)
 {
     char buffer[_MAX_PATH+1];
+    char errBuffer[_MAX_PATH+100];
     time_t ltime;
     struct tm *now;
     long result;
@@ -1774,6 +1771,11 @@
 
     sprintf(buffer, "%s\\%s-wininst.log", dir, meta_name);
     logfile = fopen(buffer, "a");
+    if (logfile==NULL) {
+        sprintf(errBuffer, "Failed to open log file '%s'", buffer);
+        MessageBox(GetFocus(), errBuffer, "Can't open log file", MB_OK);
+        return FALSE;
+    }
     time(&ltime);
     now = localtime(&ltime);
     strftime(buffer, sizeof(buffer),
@@ -1852,9 +1854,10 @@
     strftime(buffer, sizeof(buffer),
              "*** Installation finished %Y/%m/%d %H:%M ***\n",
              localtime(&ltime));
-    fprintf(logfile, buffer);
-    if (logfile)
+    if (logfile) {
+        fprintf(logfile, buffer);
         fclose(logfile);
+    }
 }
 
 BOOL CALLBACK
@@ -2462,9 +2465,13 @@
     char *dllname;
     char *scriptname;
     static char lastscript[MAX_PATH];
+    int lendllname; // includes \0
 
 /* Format is 'Run Scripts: [pythondll]scriptname' */
-/* XXX Currently, pythondll carries no path!!! */
+/* XXX Currently, pythondll carries no path!!! The caller
+   works around this by setting the python_dir global to
+   the directory of the installation dir.
+*/
     dllname = strchr(line, '[');
     if (!dllname)
         return FALSE;
@@ -2472,6 +2479,11 @@
     scriptname = strchr(dllname, ']');
     if (!scriptname)
         return FALSE;
+    /* copy the DLL name now we know where it ends. */
+    lendllname = min(scriptname - dllname, _MAX_PATH-1);
+    strncpy(pythondll, dllname, lendllname); /* no \0 copied */
+    pythondll[lendllname+1] = '\0';
+    /* Terminate the scriptname */
     *scriptname++ = '\0';
     /* this function may be called more than one time with the same
        script, only run it one time */
@@ -2505,6 +2517,8 @@
     int nErrors = 0;
     char **lines;
     int lines_buffer_size = 10;
+    char logfiledrive[_MAX_DRIVE];
+    char logfiledir[_MAX_DIR];
 
     if (argc != 3) {
         MessageBox(NULL,
@@ -2529,6 +2543,19 @@
                    MB_OK);
         return 1; /* Error */
     }
+    /* Assume the directory with the logfile is the Python directory, so
+       when we come to load the Python dll and can't find it "globally"
+       we try here.
+    */
+    _splitpath(argv[2], logfiledrive, logfiledir, NULL, NULL);
+    strcpy(python_dir, logfiledrive);
+    strcat(python_dir, logfiledir);
+    /* trim trailing slash */
+    if (python_dir[0] && 
+        (python_dir[strlen(python_dir)-1]=='\\' || 
+         python_dir[strlen(python_dir)-1]=='/')) {
+        python_dir[strlen(python_dir)-1] = '\0';
+    }
 
     lines = (char **)malloc(sizeof(char *) * lines_buffer_size);
     if (!lines)