diff --git a/CMakeExternals/Numpy.cmake b/CMakeExternals/Numpy.cmake
index f1bd406b76..f87207622c 100644
--- a/CMakeExternals/Numpy.cmake
+++ b/CMakeExternals/Numpy.cmake
@@ -1,122 +1,127 @@
 
 if( MITK_USE_Python )
 
   option(MITK_USE_NUMPY "Use the numpy python library" OFF)
 
   # always build numpy in this case
   if(NOT MITK_USE_SYSTEM_PYTHON)
     set(MITK_USE_NUMPY ON CACHE BOOL "Use the numpy python library" FORCE)
   endif()
 
   if(MITK_USE_NUMPY)
     # Sanity checks
     if(DEFINED Numpy_DIR AND NOT EXISTS ${Numpy_DIR})
       message(FATAL_ERROR "Numpy_DIR variable is defined but corresponds to non-existing directory")
     endif()
 
     if( NOT DEFINED Numpy_DIR )
       set(proj Numpy)
       set(proj_DEPENDENCIES )
       set(Numpy_DEPENDS ${proj})
 
       if(NOT MITK_USE_SYSTEM_PYTHON)
         list(APPEND proj_DEPENDENCIES Python)
       endif()
 
       set(_numpy_env
           "
           set(ENV{F77} \"\")
           set(ENV{F90} \"\")
           set(ENV{FFLAGS} \"\")
           set(ENV{ATLAS} \"None\")
           set(ENV{BLAS} \"None\")
           set(ENV{LAPACK} \"None\")
           set(ENV{MKL} \"None\")
           ")
 
       set(_external_python_project ${CMAKE_BINARY_DIR}/mitkExternalPythonProject.cmake)
       file(WRITE ${_external_python_project}
           "
           ${_numpy_env}
           set(ENV{VS_UNICODE_OUTPUT} \"\")
           set(ENV{CC} \"${CMAKE_C_COMPILER} ${CMAKE_C_COMPILER_ARG1}\")
           set(ENV{CFLAGS} \"${CMAKE_C_FLAGS} ${CMAKE_C_FLAGS_RELEASE}\")
           set(ENV{CXX} \"${CMAKE_CXX_COMPILER} ${CMAKE_CXX_COMPILER_ARG1}\")
           set(ENV{CXXFLAGS} \"${CMAKE_CXX_FLAGS} ${CMAKE_CXX_FLAGS_RELEASE}\")
           set(ENV{LDFLAGS} \"${CMAKE_LINKER_FLAGS} ${CMAKE_LINKER_FLAGS_RELEASE}\")
 
           function(MITK_PYTHON_BUILD_STEP proj step)
              set(_command \${ARGN})
 
-             message(\"Running \${proj} \${step}: \${_command}\")
+             message(\"Running \${proj} \${step}:${PYTHON_EXECUTABLE} \${_command}\")
 
              execute_process(
-                COMMAND ${PYTHON_EXECUTABLE} setup.py config
+                COMMAND ${PYTHON_EXECUTABLE} \${_command}
                 WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/\${proj}-src
                 RESULT_VARIABLE result
                 OUTPUT_VARIABLE output
                 ERROR_VARIABLE error
              )
              set(output_file \"${CMAKE_BINARY_DIR}/\${proj}_\${step}_step_output.txt\")
              file(WRITE \${output_file} \${output})
 
              set(error_file \"${CMAKE_BINARY_DIR}/\${proj}_\${step}_step_error.txt\")
              file(WRITE \${error_file} \${error})
 
              if(NOT \${result} EQUAL 0)
                message(FATAL_ERROR \"Error in: \${proj}: \${error}\")
              endif()
            endfunction()
           ")
       # configure step
       set(_configure_step ${CMAKE_BINARY_DIR}/${proj}_configure_step.cmake)
       file(WRITE ${_configure_step}
          "include(\"${_external_python_project}\")
-          file(WRITE \"${CMAKE_BINARY_DIR}/${proj}/site.cfg\" \"\")
+          file(WRITE \"${CMAKE_BINARY_DIR}/${proj}-src/site.cfg\" \"\")
           MITK_PYTHON_BUILD_STEP(${proj} configure setup.py config)
          ")
 
       # build step
       set(_build_step ${CMAKE_BINARY_DIR}/${proj}_build_step.cmake)
       file(WRITE ${_build_step}
          "include(\"${_external_python_project}\")
-          MITK_PYTHON_BUILD_STEP(${proj} configure setup.py build --fcompiler=none)
+          MITK_PYTHON_BUILD_STEP(${proj} build setup.py build --fcompiler=none)
+         ")
+
+      # install step
+      set(_install_dir "${CMAKE_BINARY_DIR}/${proj}-install")
+      if(WIN32)
+        STRING(REPLACE "/" "\\\\" _install_dir "${CMAKE_BINARY_DIR}/${proj}-install")
+      endif()
+      set(_install_step ${CMAKE_BINARY_DIR}/${proj}_install_step.cmake)
+      file(WRITE ${_install_step}
+         "include(\"${_external_python_project}\")
+          MITK_PYTHON_BUILD_STEP(${proj} install setup.py install --prefix=${_install_dir})
          ")
 
       #set(Numpy_URL "https://dl.dropboxusercontent.com/u/8367205/ExternalProjects/numpy-1.6.1.tar.gz")
       #set(Numpy_MD5 "2bce18c08fc4fce461656f0f4dd9103e")
       set(Numpy_URL "https://dl.dropboxusercontent.com/u/8367205/ExternalProjects/numpy-1.4.1.tar.gz")
       set(Numpy_MD5 "5c7b5349dc3161763f7f366ceb96516b")
 
-      set(_install_dir "${CMAKE_BINARY_DIR}/${proj}-install")
-
-      if(WIN32)
-        STRING(REPLACE "/" "\\" _install_dir "${CMAKE_BINARY_DIR}/${proj}-install")
-      endif()
-
       ExternalProject_Add(${proj}
         URL ${Numpy_URL}
         URL_MD5 ${Numpy_MD5}
         SOURCE_DIR ${proj}-src
         PREFIX ${proj}-cmake
         BUILD_IN_SOURCE 1
         INSTALL_DIR ${CMAKE_BINARY_DIR}/${proj}-install
         CONFIGURE_COMMAND ${CMAKE_COMMAND} -P ${_configure_step}
         BUILD_COMMAND   ${CMAKE_COMMAND} -P ${_build_step}
-        INSTALL_COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_BINARY_DIR}/${proj}-src/setup.py install --prefix=${_install_dir}
+        INSTALL_COMMAND ${CMAKE_COMMAND} -P ${_install_step}
 
         DEPENDS
           ${${proj}_DEPENDENCIES}
       )
 
       if(WIN32)
         set(Numpy_DIR ${CMAKE_BINARY_DIR}/${proj}-install/Lib/site-packages)
       else()
         set(Numpy_DIR ${CMAKE_BINARY_DIR}/${proj}-install/lib/python2.7/site-packages)
       endif()
     else()
       mitkMacroEmptyExternalProject(${proj} "${proj_DEPENDENCIES}")
     endif()
   endif()
 endif()