Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As Long, ByVal lpWindowName As Long) As Long

'В форме
Private Sub Form_Load()
    Me.AutoRedraw = True
    EnumWindows AddressOf EnumWindowsProc, ByVal  0 &
End Sub

'В модуле
Declare Function EnumWindows Lib "user32" (ByVal lpEnumFunc As Long, ByVal lParam As Long) As Boolean
Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" (ByVal hwnd As Long, ByVal lpString As String, ByVal cch As Long) As Long
Declare Function GetWindowTextLength Lib "user32" Alias "GetWindowTextLengthA" (ByVal hwnd As Long) As Long

Public Function EnumWindowsProc(ByVal hwnd As Long, ByVal lParam As Long) As Boolean
    Dim sSave As String, Ret As Long
    Ret = GetWindowTextLength(hwnd)
    sSave = Space(Ret)
    GetWindowText hwnd, sSave, Ret +  1 
    Form1.Print Str$(hwnd) + " " + sSave
    'continue enumeration
    EnumWindowsProc = True
End Function

Declare Function EnumWindows Lib "user32" (ByVal lpEnumFunc As Long, ByVal lParam As Long) As Boolean
Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" (ByVal hwnd As Long, ByVal lpString As String, ByVal cch As Long) As Long
Declare Function GetWindowTextLength Lib "user32" Alias "GetWindowTextLengthA" (ByVal hwnd As Long) As Long
Declare Function PostMessage Lib "user32" Alias "PostMessageA" (ByVal hwnd As Long, _
  ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Const WM_CLOSE = &H10

Public Function EnumWindowsProc(ByVal hwnd As Long, ByVal lParam As Long) As Boolean
    Dim sSave As String, Ret As Long
    Ret = GetWindowTextLength(hwnd)
    sSave = Space(Ret)
    GetWindowText hwnd, sSave, Ret +  1 
    Form1.Print Str$(hwnd) + " " + sSave
    If InStr( 1 , sSave, "Notepad", vbTextCompare) <>  0  Then
        Call PostMessage(hwnd, WM_CLOSE,  0 &,  0 &)
        EnumWindowsProc = False
    Else
        EnumWindowsProc = True
    End If
End Function