Creating and removing an environment in Anaconda Prompt (anaconda3)

(base) C:\Users\ashish>conda create --name test_env
WARNING conda.base.context:use_only_tar_bz2(632): Conda is constrained to only using the old .tar.bz2 file format because you have conda-build installed, and it is <3.18.3.  Update or remove conda-build to get smaller downloads and faster extractions.
Collecting package metadata (repodata.json): done
Solving environment: done


==> WARNING: A newer version of conda exists. <==
  current version: 4.7.5
  latest version: 4.8.2

Please update conda by running

    $ conda update -n base -c defaults conda



## Package Plan ##

  environment location: C:\Users\ashish\AppData\Local\Continuum\anaconda3\envs\test_env

Proceed ([y]/n)? y

Preparing transaction: done
Verifying transaction: done
Executing transaction: done
#
# To activate this environment, use
#
#     $ conda activate test_env
#
# To deactivate an active environment, use
#
#     $ conda deactivate


(base) C:\Users\ashish>conda activate test_env

(test_env) C:\Users\ashish>python
Python 3.7.4 (default, Aug  9 2019, 18:34:13) [MSC v.1915 64 bit (AMD64)] :: Anaconda, Inc. on win32

Warning:
This Python interpreter is in a conda environment, but the environment has
not been activated.  Libraries may fail to load.  To activate this environment
please see https://conda.io/activation

Type "help", "copyright", "credits" or "license" for more information.
>>> exit()



(test_env) C:\Users\ashish>conda deactivate

(base) C:\Users\ashish>conda remove --name test_env --all

Remove all packages in environment C:\Users\ashish\AppData\Local\Continuum\anaconda3\envs\test_env:


PackagesNotFoundError: The following packages are missing from the target environment:
  -



(base) C:\Users\ashish>conda env list
# conda environments:
#
                         C:\ProgramData\Anaconda3
base                  *  C:\Users\ashish\AppData\Local\Continuum\anaconda3
test_env                 C:\Users\ashish\AppData\Local\Continuum\anaconda3\envs\test_env
tf                       C:\Users\ashish\AppData\Local\Continuum\anaconda3\envs\tf


(base) C:\Users\ashish>

base) C:\Users\ashish>conda env remove --name test_env

Remove all packages in environment C:\Users\ashish\AppData\Local\Continuum\anaconda3\envs\test_env:


(base) C:\Users\ashish>conda env list
# conda environments:
#
                         C:\ProgramData\Anaconda3
base                  *  C:\Users\ashish\AppData\Local\Continuum\anaconda3
tf                       C:\Users\ashish\AppData\Local\Continuum\anaconda3\envs\tf