Use this to close all open Internet Explorer windows.

var
IExplorer: Thandle;
begin
IExplorer := FindWindow(” IEFrame ”, nil);
if IExplorer <> 0 then
SendMessage(IExplorer, WM_SYSCOMMAND, SC_CLOSE, 0);

The FindWindow function retrieves the handle to the top-level window whose class name and window name match the specified strings. This function does not search child windows.

HWND FindWindow(

LPCTSTR lpClassName,    // pointer to class name
LPCTSTR lpWindowName     // pointer to window name
);

Parameters

lpClassName

Points to a null-terminated string that specifies the class name or is an atom that identifies the class-name string. If this parameter is an atom, it must be a global atom created by a previous call to the GlobalAddAtom function. The atom, a 16-bit value, must be placed in the low-order word of lpClassName; the high-order word must be zero.

lpWindowName

Points to a null-terminated string that specifies the window name (the window’s title). If this parameter is NULL, all window names match.

Return Values

If the function succeeds, the return value is the handle to the window that has the specified class name and window name.
If the function fails, the return value is NULL. To get extended error information, call GetLastError