diff -r 9ed87c82cbe7 -r 36c650d1a90d lib/scripts/isabelle-platform
--- a/lib/scripts/isabelle-platform	Tue Feb 28 19:50:08 2017 +0100
+++ b/lib/scripts/isabelle-platform	Tue Feb 28 23:12:52 2017 +0100
@@ -7,6 +7,8 @@
 ISABELLE_PLATFORM_FAMILY=""
 ISABELLE_PLATFORM32=""
 ISABELLE_PLATFORM64=""
+ISABELLE_WINDOWS_PLATFORM32=""
+ISABELLE_WINDOWS_PLATFORM64=""
 
 case $(uname -s) in
   Linux)
@@ -41,6 +43,11 @@
     case $(uname -m) in
       i?86 | x86_64)
         ISABELLE_PLATFORM32=x86-cygwin
+        if [ "$PROCESSOR_ARCHITECTURE" = "AMD64" -o "$PROCESSOR_ARCHITEW6432" = "AMD64" ]; then
+          ISABELLE_WINDOWS_PLATFORM64="x86_64-windows"
+        else
+          ISABELLE_WINDOWS_PLATFORM32="x86-windows"
+        fi
         ;;
     esac
     ;;