请问：如何枚举当前打开的窗口名称，指WINDOWS进程

Option Explicit
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 GetParent Lib "user32" (ByVal hwnd 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 Declare Function IsWindowVisible Lib "user32" (ByVal hwnd As Long) As Long
Private Const GW_HWNDNEXT = 2
Private Const GW_CHILD = 5
Private Sub Form_Load()
       '使用前在窗体上创建一个ListBox控件，名称为List1
       Dim hwnd As Long
       hwnd = GetDesktopWindow() '返回桌面的句柄
       hwnd = GetWindow(hwnd, GW_CHILD) '返回桌面的第一个子窗口
       Dim sWindowText As String
       Dim r As Long
       Do While hwnd  0
               If GetParent(hwnd) = 0 Then '顶层窗口
                       If IsWindowVisible(hwnd) Then '窗口状态是显示的
                               sWindowText = String(255, Chr(0))
                               r = GetWindowText(hwnd, sWindowText, 255) '返回窗口的标题
                               sWindowText = Left(sWindowText, r)
                               If sWindowText  "" Then List1.AddItem sWindowText
                       End If
               End If
               hwnd = GetWindow(hwnd, GW_HWNDNEXT) '返回下一个窗口
       Loop
End Sub