Reinstall PyEnv-Win:

Invoke-WebRequest -UseBasicParsing `
    -Uri "https://raw.githubusercontent.com/pyenv-win/pyenv-win/master/pyenv-win/install-pyenv-win.ps1" `
    -OutFile "./install-pyenv-win.ps1"; &"./install-pyenv-win.ps1"

Alternative:

Add the following to current user Path:

See pyenv for Windows