> Error conda.core.link:_execute_actions(337): An ERROR occurred while installing package ‘;
> Error conda.core.link:_execute_actions(337): An ERROR occurred while installing package ‘; ERROR conda.core.link:_execute_actions(337): An ERROR occurred while the package was installed;

Type in the following code in CMD:

conda install mingw libpython

The following error occurred:

The following NEW packages will be INSTALLED:

    conda-package-handling: 1.7.2-py36h76e460a_0
    libpython:              2.1-py36_0
    mingw:                  4.7-1
    tqdm:                   4.55.1-pyhd3eb1b0_0

The following packages will be UPDATED:

    conda:                  4.3.30-py36h7e176b0_0 --> 4.9.2-py36haa95532_0
    conda-env:              2.6.0-h36134e3_1      --> 2.6.0-1
    menuinst:               1.4.10-py36h42196fb_0 --> 1.4.16-py36he774522_1
    pycosat:                0.6.2-py36hf17546d_1  --> 0.6.3-py36h2bbff1b_0
    vc:                     14-h2379b0c_2         --> 14.2-h21ff451_1
    vs2015_runtime:         14.0.25123-hd4c4e62_2 --> 14.27.29016-h5e58377_2

Proceed ([y]/n)?y

libpython-2.1- 100% |###############################| Time: 0:00:37   1.08 MB/s
ERROR conda.core.link:_execute_actions(337): An error occurred while installing package 'defaults::tqdm-4.55.1-pyhd3eb1b0_0'.
CondaError: Cannot link a source that does not exist. D:\software\Anaconda\Scripts\conda.exe
Running `conda clean --packages` may resolve your problem.
Attempting to roll back.

Solutions:

conda clean --all

Type in the following code again:

conda install mingw libpython

Installation successful!