Windows 10 System Start menu Sometimes it's not going to open.

After you upgrade Windows 10, the Start menu cannot be opened, as shown in the following illustration.

Operation Steps:
test Environment: Windows Ten Pro Insider Preview

1, since the Start menu can not open we now find a temporary solution, we right click on the taskbar blank or press CTRL+SHIFT+ESC, "task Manager" as shown in the following image;

2, and then in mission management, we switch Classic mode and then we find the Desktop Window Manager (English System for desktop Window Manager), right click "End Task" and then we select "Discard unsaved data and close" and click "Close" as shown in the following figure.

3, after the end of the process, we then click on the Task Manager window "file"---"Run a new task", input DWM carriage can be, now the Start menu is also available.