diff --git a/Configure.py b/Configure.py
index 956d17f..08264ad 100755
--- a/Configure.py
+++ b/Configure.py
@@ -27,6 +27,7 @@ import pprint
 import re
 import glob
 
+import platform
 import mf
 import bindepend
 import Build
@@ -38,6 +39,12 @@ is24 = hasattr(sys, "version_info") and sys.version_info[:2] >= (2,4)
 is26 = hasattr(sys, "version_info") and sys.version_info[:2] >= (2,6)
 cygwin = sys.platform == 'cygwin'
 
+if iswin and platform.architecture()[0] != "32bit":
+    print "ERROR: PyInstaller does not support Windows 64-bit"
+    print "Subscribe to this ticket for more information:"
+    print "    http://www.pyinstaller.org/ticket/25"
+    sys.exit(2)
+
 if iswin and is26:
     print "ERROR: Python 2.6+ on Windows is unsupported by PyInstaller 1.4"
     print "Try the snapshot available on this page:"