diff -r 555f5fe53341 Lib/multiprocessing/connection.py
--- a/Lib/multiprocessing/connection.py	Tue Apr 03 09:16:46 2012 +0200
+++ b/Lib/multiprocessing/connection.py	Tue Apr 03 12:08:34 2012 +0300
@@ -111,6 +111,12 @@
     if sys.platform != 'win32' and family == 'AF_PIPE':
         raise ValueError('Family %s is not recognized.' % family)
 
+    if sys.platform == 'win32' and family == 'AF_UNIX':
+        # double check
+        if not hasattr(socket, family):
+            raise ValueError('Family %s is not recognized.' % family)    
+        
+
 
 def address_type(address):
     '''
diff -r 555f5fe53341 Lib/test/test_multiprocessing.py
--- a/Lib/test/test_multiprocessing.py	Tue Apr 03 09:16:46 2012 +0200
+++ b/Lib/test/test_multiprocessing.py	Tue Apr 03 12:08:34 2012 +0300
@@ -2649,6 +2649,11 @@
         with self.assertRaises(ValueError):
             multiprocessing.connection.Listener(r'\\.\test')
 
+    @unittest.skipUnless(WIN32, "skipped on non-Windows platforms")
+    def test_invalid_family_win32(self):
+        with self.assertRaises(ValueError):
+            multiprocessing.connection.Listener('/var/test.pipe')
+
 
 testcases_other = [OtherTest, TestInvalidHandle, TestInitializers,
                    TestStdinBadfiledescriptor, TestWait, TestInvalidFamily]