How to Set Python Environment Variables on Windows in 10 Simple Steps

Even after installing Python, you might encounter an error when running python from the command line because the environment variable is not set. This article shows how to configure the Python PATH on Windows.

Confirm that Python is installed and locate its installation directory (e.g., C:\Python27 or C:\Python38 ).

Copy the full installation path. You can click the address bar in the folder window to select the path.

Press Ctrl+C to copy the path.

The copied path will look like C:\Python27 . Use the path that matches your installation.

On the desktop, open "My Computer", right‑click and choose "Properties".

In the System window, click "Advanced system settings" on the left.

In the "System Properties" dialog, go to the "Advanced" tab and click the "Environment Variables" button.

In the "Environment Variables" window, select the "Path" variable under System variables and click "Edit".

Append a semicolon and the copied Python path to the end of the variable value (e.g., ;C:\Python27 ), then click OK on all dialogs.

Open a new Command Prompt window and run python again; the interpreter should start, confirming the PATH is set correctly.

After completing these steps, you can use Python from any command line without issues.