diff --git a/Modules/CPack.cmake b/Modules/CPack.cmake
index bb696af..5891158 100644
--- a/Modules/CPack.cmake
+++ b/Modules/CPack.cmake
@@ -370,7 +370,13 @@ cpack_set_if_not_set(CPACK_SYSTEM_NAME "${__cpack_system_name}")
 
 # Root dir: default value should be the string literal "$PROGRAMFILES"
 # for backwards compatibility. Projects may set this value to anything.
+# When creating 64 bit binaries we set the default value to "$PROGRAMFILES64"
 set(__cpack_root_default "$PROGRAMFILES")
+if(${__cpack_system_name} MATCHES Windows)
+  if(CMAKE_CL_64)
+    set(__cpack_root_default "$PROGRAMFILES64")
+  endif()
+endif()
 cpack_set_if_not_set(CPACK_NSIS_INSTALL_ROOT "${__cpack_root_default}")
 
 # <project>-<major>.<minor>.<patch>-<release>-<platform>.<pkgtype>

Index: cmake/Modules/CPack.cmake
===================================================================
--- cmake.orig/Modules/CPack.cmake
+++ cmake/Modules/CPack.cmake
@@ -363,7 +363,13 @@ cpack_set_if_not_set(CPACK_SYSTEM_NAME "
 
 # Root dir: default value should be the string literal "$PROGRAMFILES"
 # for backwards compatibility. Projects may set this value to anything.
+# When creating 64 bit binaries we set the default value to "$PROGRAMFILES64"
 set(__cpack_root_default "$PROGRAMFILES")
+if(${__cpack_system_name} MATCHES Windows)
+  if(CMAKE_SIZEOF_VOID_P EQUAL 8)
+    set(__cpack_root_default "$PROGRAMFILES64")
+  endif()
+endif()
 cpack_set_if_not_set(CPACK_NSIS_INSTALL_ROOT "${__cpack_root_default}")
 
 # <project>-<major>.<minor>.<patch>-<release>-<platform>.<pkgtype>

From ecaee7caca4e3d4528e643736c0620e785e84153 Mon Sep 17 00:00:00 2001
Message-Id: <ecaee7caca4e3d4528e643736c0620e785e84153.1423080725.git.brad.king@kitware.com>
From: Brad King <brad.king@kitware.com>
Date: Wed, 4 Feb 2015 15:09:18 -0500
Subject: [PATCH] CPack: Fix NSIS default 64-bit Windows install directory
 (#14211)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

When targeting Windows with a 64-bit architecture, use "$PROGRAMFILES64"
to get the Program Files folder.  Use CMAKE_SIZEOF_VOID_P to check for
the architecture size instead of CMAKE_CL_64 because the latter is not
defined for all compilers.

Inspired-by: Hugh Sorby <h.sorby@auckland.ac.nz>
Inspired-by: İsmail Dönmez <ismail@donmez.ws>
---
 Modules/CPack.cmake | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/Modules/CPack.cmake b/Modules/CPack.cmake
index 35259c4..ce1536e 100644
--- a/Modules/CPack.cmake
+++ b/Modules/CPack.cmake
@@ -352,8 +352,8 @@ if(CPACK_NSIS_MODIFY_PATH)
 endif()
 
 set(__cpack_system_name ${CMAKE_SYSTEM_NAME})
-if(${__cpack_system_name} MATCHES Windows)
-  if(CMAKE_CL_64)
+if(__cpack_system_name MATCHES "Windows")
+  if(CMAKE_SIZEOF_VOID_P EQUAL 8)
     set(__cpack_system_name win64)
   else()
     set(__cpack_system_name win32)
@@ -363,7 +363,12 @@ cpack_set_if_not_set(CPACK_SYSTEM_NAME "${__cpack_system_name}")
 
 # Root dir: default value should be the string literal "$PROGRAMFILES"
 # for backwards compatibility. Projects may set this value to anything.
-set(__cpack_root_default "$PROGRAMFILES")
+# When creating 64 bit binaries we set the default value to "$PROGRAMFILES64"
+if("x${__cpack_system_name}" STREQUAL "xwin64")
+  set(__cpack_root_default "$PROGRAMFILES64")
+else()
+  set(__cpack_root_default "$PROGRAMFILES")
+endif()
 cpack_set_if_not_set(CPACK_NSIS_INSTALL_ROOT "${__cpack_root_default}")
 
 # <project>-<major>.<minor>.<patch>-<release>-<platform>.<pkgtype>
-- 
2.1.4