How to Fix pip.exe Permission Errors in Python Virtual Environments on Windows

A common issue on Windows occurs when pip.exe inside a Python virtual environment returns an 'Access is denied' error, even though running python -m pip works fine. The root cause is not a file permission problem but rather a corrupted or outdated launcher stub inside the virtual environment's Scripts folder. This typically happens after installing or uninstalling multiple Python versions, moving the virtual environment, or having conflicting PATH entries. The recommended fix is to run python -m venv --upgrade on the existing environment to regenerate all launchers using the current Python version. As a best practice, users should always invoke pip via python -m pip instead of calling pip.exe directly to avoid launcher-related issues on Windows.