diff --git a/hg b/hg
--- a/hg
+++ b/hg
@@ -21,6 +21,17 @@
         libdir = os.path.abspath(libdir)
     sys.path.insert(0, libdir)
 
+# Make `pip install --user ...` packages available to the official Windows
+# build.  Most py2 packaging installs directly into the system python
+# environment, so no changes are necessary for other platforms.  The Windows
+# py2 package uses py2exe, which lacks a `site` module.  Hardcode it according
+# to the documentation.
+if getattr(sys, 'frozen', None) == 'console_exe':
+    vi = sys.version_info
+    sys.path.append(os.path.join(os.environ['APPDATA'], 'Python',
+                                 'Python%d%d' % (vi[0], vi[1]),
+                                 'site-packages'))
+
 from hgdemandimport import tracing
 
 with tracing.log('hg script'):