I too had to face the same problem. This worked for me. Right click and run as admin than run usual command to install. But first run update command to update the pip
Well, in my case the problem had a different cause, the Windows path Length Check this.
I was installing a library on a virtualenv which made the path get longer. As the library was installed, it created some files under site-packages. This made the path exceed Windows limit throwing this error.
On Windows this has worked for me. From the command line, specify the path to the exe for Python:
& "C:/Program Files (x86)/Python37-32/python.exe" -m pip install --upgrade pip --user