O Ipython está trabalhando no prompt de comando, mas não no navegador

Estou usando um laptop Windows 8 de 64 bits. Eu já tenho python 2.7 no meu pc. Então eu instalei o Ipython usando o easy_install. Agora posso ver um arquivo de aplicativo ipython em C: \ Python27 \ Scripts. Quando executo esse arquivo, ele abre meu cmd e posso escrever código. No entanto, quando eu digoIpython notebook no cmd da mesma pasta, ele não abre o notebook em um navegador e gera o seguinte erro -

C:\Users\UserName>cd C:\Python27\Scripts\

C:\Python27\Scripts>Ipython notebook
Traceback (most recent call last):
  File "C:\Python27\Scripts\ipython-script.py", line 9, in <module>
    load_entry_point('ipython==1.2.0', 'console_scripts', 'ipython')()
  File "C:\Python27\lib\site-packages\ipython-1.2.0-py2.7.egg\IPython\__init__.p
y", line 118, in start_ipython
    return launch_new_instance(argv=argv, **kwargs)
  File "C:\Python27\lib\site-packages\ipython-1.2.0-py2.7.egg\IPython\config\app
lication.py", line 544, in launch_instance
    app.initialize(argv)
  File "<string>", line 2, in initialize
  File "C:\Python27\lib\site-packages\ipython-1.2.0-py2.7.egg\IPython\config\app
lication.py", line 89, in catch_config_error
    return method(app, *args, **kwargs)
  File "C:\Python27\lib\site-packages\ipython-1.2.0-py2.7.egg\IPython\terminal\i
papp.py", line 312, in initialize
    super(TerminalIPythonApp, self).initialize(argv)
  File "<string>", line 2, in initialize
  File "C:\Python27\lib\site-packages\ipython-1.2.0-py2.7.egg\IPython\config\app
lication.py", line 89, in catch_config_error
    return method(app, *args, **kwargs)
  File "C:\Python27\lib\site-packages\ipython-1.2.0-py2.7.egg\IPython\core\appli
cation.py", line 373, in initialize
    self.parse_command_line(argv)
  File "C:\Python27\lib\site-packages\ipython-1.2.0-py2.7.egg\IPython\terminal\i
papp.py", line 307, in parse_command_line
    return super(TerminalIPythonApp, self).parse_command_line(argv)
  File "<string>", line 2, in parse_command_line
  File "C:\Python27\lib\site-packages\ipython-1.2.0-py2.7.egg\IPython\config\app
lication.py", line 89, in catch_config_error
    return method(app, *args, **kwargs)
  File "C:\Python27\lib\site-packages\ipython-1.2.0-py2.7.egg\IPython\config\app
lication.py", line 474, in parse_command_line
    return self.initialize_subcommand(subc, subargv)
  File "<string>", line 2, in initialize_subcommand
  File "C:\Python27\lib\site-packages\ipython-1.2.0-py2.7.egg\IPython\config\app
lication.py", line 89, in catch_config_error
    return method(app, *args, **kwargs)
  File "C:\Python27\lib\site-packages\ipython-1.2.0-py2.7.egg\IPython\config\app
lication.py", line 405, in initialize_subcommand
    subapp = import_item(subapp)
  File "C:\Python27\lib\site-packages\ipython-1.2.0-py2.7.egg\IPython\utils\impo
rtstring.py", line 42, in import_item
    module = __import__(package, fromlist=[obj])
  File "C:\Python27\lib\site-packages\ipython-1.2.0-py2.7.egg\IPython\html\noteb
ookapp.py", line 36, in <module>
    check_for_zmq('2.1.11', 'IPython.html')
  File "C:\Python27\lib\site-packages\ipython-1.2.0-py2.7.egg\IPython\utils\zmqr
elated.py", line 37, in check_for_zmq
    raise ImportError("%s requires pyzmq >= %s"%(required_by, minimum_version))
ImportError: IPython.html requires pyzmq >= 2.1.11

C:\Python27\Scripts>