title: Problems with Jupyter labextensions in installing Jupyter Widgets
body: <p>I'm having trouble installing Jupyter Widgets for the Jupyter notebook. I've been following the instructions from here: <a href="http://ipywidgets.readthedocs.io/en/stable/user_install.html" rel="nofollow noreferrer">http://ipywidgets.readthedocs.io/en/stable/user_install.html</a> but have stumbled at the JupyterLab extension step (3rd line of code below):</p>
  
  <pre><code>pip install ipywidgets
  jupyter nbextension enable --py widgetsnbextension
  jupyter labextension install @jupyter-widgets/jupyterlab-manager
  </code></pre>
  
  <p>The error message is: </p>
  
  <pre><code>Error executing Jupyter command 'labextensions': [Errno 'jupyter-     labextensions' not found] 2
  </code></pre>
  
  <p>As required above I've installed nodejs and it's added to my system PATH. Running the command line as an administrator and:</p>
  
  <pre><code>C:\Python\Scripts&gt; jupyter labextension list 
  </code></pre>
  
  <p>gives the same error message as above. However, the Jupyterlab website mentions:</p>
  
  <blockquote>
    <p>The base JupyterLab application comes with core set of extensions, which 
    provide the Notebook, Terminal, Text Editor, etc</p>
  </blockquote>
  
  <p>So given that I already launch Jupyter notebook with ...</p>
  
  <pre><code>C:\Python\Scripts&gt; jupyter notebook 
  </code></pre>
  
  <p>... shouldn't labextensions be installed already? Perhaps I'm not calling it from the right directory? Any suggestions would be helpful. Thanks</p>
  
  <p>PS: conda is not an option for me at the moment because it runs foul of my anti-virus</p>