Can't run any ipynb files using Jupyter Lab or Jupyter Notebook (FileNotFoundError: [WinError 2] The system cannot find the file specified)

Question

I have JupyterLab/JupyterNotebook running on Win10, along with Python and PyCharm on the side on Windows 10. Whenever I launch JupyterLab/JupyterNotebook I get the error stated below. I have tried reinstalling the Anaconda-distribution or any other instances of Python but it gives me the same error every time I launch JupyterLab/Notebook. I have also tried running it on a remote server with Win 7 but it gives me the exact same error. Part of me thinks that I made the same mistake while installing Anaconda, Python, and PyCharm and now I can't revert it back. Any suggestions?

Traceback (most recent call last):
  File "E:\anaconda3\lib\site-packages\tornado\web.py", line 1543, in _execute
    result = yield result
  File "E:\anaconda3\lib\site-packages\tornado\gen.py", line 1099, in run
    value = future.result()
  File "E:\anaconda3\lib\site-packages\tornado\gen.py", line 1107, in run
    yielded = self.gen.throw(*exc_info)
  File "E:\anaconda3\lib\site-packages\notebook\services\sessions\handlers.py", line 73, in post
    type=mtype))
  File "E:\anaconda3\lib\site-packages\tornado\gen.py", line 1099, in run
    value = future.result()
  File "E:\anaconda3\lib\site-packages\tornado\gen.py", line 1107, in run
    yielded = self.gen.throw(*exc_info)
  File "E:\anaconda3\lib\site-packages\notebook\services\sessions\sessionmanager.py", line 79, in create_session
    kernel_id = yield self.start_kernel_for_session(session_id, path, name, type, kernel_name)
  File "E:\anaconda3\lib\site-packages\tornado\gen.py", line 1099, in run
    value = future.result()
  File "E:\anaconda3\lib\site-packages\tornado\gen.py", line 1107, in run
    yielded = self.gen.throw(*exc_info)
  File "E:\anaconda3\lib\site-packages\notebook\services\sessions\sessionmanager.py", line 92, in start_kernel_for_session
    self.kernel_manager.start_kernel(path=kernel_path, kernel_name=kernel_name)
  File "E:\anaconda3\lib\site-packages\tornado\gen.py", line 1099, in run
    value = future.result()
  File "E:\anaconda3\lib\site-packages\tornado\gen.py", line 315, in wrapper
    yielded = next(result)
  File "E:\anaconda3\lib\site-packages\notebook\services\kernels\kernelmanager.py", line 148, in start_kernel
    super(MappingKernelManager, self).start_kernel(**kwargs)
  File "E:\anaconda3\lib\site-packages\jupyter_client\multikernelmanager.py", line 110, in start_kernel
    km.start_kernel(**kwargs)
  File "E:\anaconda3\lib\site-packages\jupyter_client\manager.py", line 259, in start_kernel
    **kw)
  File "E:\anaconda3\lib\site-packages\jupyter_client\manager.py", line 204, in _launch_kernel
    return launch_kernel(kernel_cmd, **kw)
  File "E:\anaconda3\lib\site-packages\jupyter_client\launcher.py", line 128, in launch_kernel
    proc = Popen(cmd, **kwargs)
  File "E:\anaconda3\lib\subprocess.py", line 709, in __init__
    restore_signals, start_new_session)
  File "E:\anaconda3\lib\subprocess.py", line 997, in _execute_child
    startupinfo)
FileNotFoundError: [WinError 2] The system cannot find the file specified

Answer 1

It is probably because you delete an env and there is still a reference to that env. To solve the problem, run the following command on the command prompt:

python -m ipykernel install --user

Hope this helps :)

Answer 2

I had exactly the same problem. I found the solution here (please follow the link for further explanation), by typing this in cmd in my virtual environment the problem was solved:

python -m ipykernel install --user

I hope it will help