1. Right-click (Windows XP) or double-click (Windows 7) on the “My Computer” icon and select “Properties” or “System Properties”.
2. Click on the “Advanced” tab, then on the “Environment Variables” button.
3. A dialogue window will pop up. Edit the path variable in the top text box, adding your entry (c:\mingw\bin, for example) to the end. If there is no PATH variable listed there, create it. Path entries are separated by semicolons in Windows, so if the PATH variable already exists and has entries, you must separate your entry from the preceding one with a semicolon. As a guide for the format, you may examine the system PATH variable in the bottom text box. Do not edit the system PATH, however, as this can lead to unintended consequences for your computer.