Microsoft issued a hotfix for the wow64 emulator bug. note this in the readme and link to the hotfix.

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 Change: 186820
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mps/readme.txt

@@ -74,6 +74,12 @@ The MPS is currently supported for deployment on:
 
 - Windows XP or later on IA-32 and x86-64, using Microsoft Visual C/C++;
 
+  If you are running a multi-threaded 32-bit application on 64-bit
+  Windows 7 via the WOW64 emulator, then you need this hotfix from
+  Microsoft: `<http://support.microsoft.com/kb/2864432/en-us>`__. (See
+  `<http://zachsaw.blogspot.co.uk/2010/11/wow64-bug-getthreadcontext-may-return.html>`__
+  for a description of the problem.)
+
 - Linux (Ubuntu 12 and 13 known good, otherwise YMMV) on IA-32 using
   GCC and on x86-64 using GCC or Clang/LLVM;
 
@@ -81,13 +87,6 @@ The MPS is currently supported for deployment on:
 
 - Mac OS X 10.4 or later, on IA-32 and x86-64, using Clang/LLVM.
 
-The MPS will *not* work in a multi-threaded 32-bit application on 64-bit
-Windows 7.  This is due to a serious fault in Microsoft's WOW64 emulator
-that we are powerless to correct.  It is due to be fixed in Windows 8.
-(See `WOW64 bug: GetThreadContext() may return stale contents
-<http://zachsaw.blogspot.co.uk/2010/11/wow64-bug-getthreadcontext-may-
-return.html>`__.)
-
 The MPS is highly portable and has run on many other processors and
 operating systems in the past (see `Building the MPS
 <manual/guide/build.html>`__). Most of the MPS is written in very pure
@@ -129,6 +128,7 @@ Document History
 2012-09-05  RB_    Considerably reduced ready for version 1.110.  Now 
                    brought to you in glorious reStructuredText.
 2014-01-13  GDR_   Updated supported platforms.
+2014-07-04  GDR_   Link to hotfix for WOW64 bug.
 ==========  =====  ======================================================
 
 .. _GDR: mailto:gdr@ravenbrook.com