grass 7 startup problem

[neuba]

We have grass 7 startup problem in windows 8.

Cleaning up temporary files...
Starting GRASS GIS...
ATTENTION: Le verrouillage concurrent de jeux de cartes n'est pas pris en
           charge dans Windows

          __________  ___   __________    _______________
         / ____/ __ \/   | / ___/ ___/   / ____/  _/ ___/
        / / __/ /_/ / /| | \__ \\_  \   / / __ / / \__ \
       / /_/ / _, _/ ___ |___/ /__/ /  / /_/ // / ___/ /
       \____/_/ |_/_/  |_/____/____/   \____/___//____/

Welcome to GRASS GIS 7.0.0
GRASS GIS homepage:                      http://grass.osgeo.org
This version running through:            Bourne Shell (C:\Program Files (x86)\GR
ASS GIS 6.4.4\msys\bin\sh.exe)
Help is available with the command:      g.manual -i
See the licence terms with:              g.version -c
Start the GUI with:                      g.gui wxpython
When ready to quit enter:                exit

Traceback (most recent call last):
  File "C:\Program Files (x86)\GRASS GIS 7.0.0\etc\grass70.py", line 1468, in <m
odule>
    default_startup()
  File "C:\Program Files (x86)\GRASS GIS 7.0.0\etc\grass70.py", line 1158, in de
fault_startup
    exit_val = subprocess.call([os.getenv('SHELL')])
  File "C:\Program Files (x86)\GRASS GIS 7.0.0\Python27\lib\subprocess.py", line
 524, in call
    return Popen(*popenargs, **kwargs).wait()
  File "C:\Program Files (x86)\GRASS GIS 7.0.0\Python27\lib\subprocess.py", line
 711, in __init__
    errread, errwrite)
  File "C:\Program Files (x86)\GRASS GIS 7.0.0\Python27\lib\subprocess.py", line
 948, in _execute_child
    startupinfo)
WindowsError: [Error 2] Le fichier spécifié est introuvable
Appuyez sur une touche pour continuer...
File "c:\program files\GRASS 7.0\etc\grass70.py" line 1468, in <module>