ACC: How to Determine When a Shelled Process Ends

How To Programmatically Close a Single Instance of a Windows-Based Program

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To programmatically close a single instance of a Windows program, use the FindWindow function to get the handle to the window that you want to close. The FindWindow function returns the handle of a top-level window with a class name and a window name that match the string parameters. The FindWindow function returns the handle of the window as a long value if it is successful, and it returns the handle of the window as a null value if it fails. To use FindWindow, you must supply the following two parameters:

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The WaitForSingleObject function requires a process handle, which is different from an hWnd. You must call GetWindowThreadProcessId to determine the ProcessID, and then pass it to the OpenProcess function to obtain a process handle.