Private Declare Function GetDesktopWindow Lib "user32" () As Long
Private Declare Function GetWindow Lib "user32" (ByVal hwnd As Long, ByVal _
    wCmd As Long) As Long
Private Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" _
    (ByVal hwnd As Long, ByVal lpString As String, ByVal cch As Long) As Long
Private Const GW_CHILD = 5
Private Const GW_HWNDNEXT = 2

Private Sub Form_Load()
Dim dhwnd As Long, hwnd As Long, wc As Long, rval As Long
Dim wname As String, index As Long
dhwnd = GetDesktopWindow()
hwnd = GetWindow(dhwnd, GW_CHILD)
wc = 1: index = 0
Do While hwnd <> 0
    wname = Space(260)
    rval = GetWindowText(hwnd, wname, 260)
    wname = Left(wname, InStr(wname, Chr(0)) - 1)
    If Len(wname) Then
        'MsgBox wname
        List1.AddItem wname, index
        index = index + 1
    End If
    hwnd = GetWindow(hwnd, GW_HWNDNEXT)
Loop
Label1.Caption = "Total number of Open Windows = " & index + 1
End Sub