Thomas Heller noticed that the wrong registry entry was written for
the DLL.  Replace
 %_SYSDEST_%\Python20.dll
with
 %_DLLDEST_%\Python20.dll.
diff --git a/PCbuild/python20.wse b/PCbuild/python20.wse
index 6e0b1b8..a09e51e 100644
--- a/PCbuild/python20.wse
+++ b/PCbuild/python20.wse
@@ -997,7 +997,7 @@
 end
 item: Edit Registry
   Key=Software\Python\PythonCore\%PY_VERSION%\Dll
-  New Value=%_SYSDEST_%\Python20.dll
+  New Value=%_DLLDEST_%\Python20.dll
   Root=2
 end
 item: Edit Registry