If we want to extend partition of Windows, we should download partition manager for free at first. After installation, we need to run it to open its main interface. The left screenshot is the main interface of this free partition manager. Here, we take extending partition D for example. To extend partition D, we should select partition D and click the functional button “Extend Partition”. Then, take operations according to prompts. When all operations are applied to computer, professional partition manager helps extend partition of Windows successfully.