Option Explicit
Dim hwndTaskbar As Long
Dim hwndStartButton As Long
Dim hbmpOriginal As Long
 
Private Declare Function FindWindowEx Lib "User32" _
  Alias "FindWindowExA" (ByVal hwnd As Long, _
  ByVal hWndChild As Long, ByVal lpszClassName As Any, _
  ByVal lpszWindow As Any) As Long
 
Private Declare Function LoadImage Lib "User32" Alias _
  "LoadImageA" (ByVal hInst As Long, _
  ByVal lpsz As String, ByVal iImageType As Long, _
  ByVal cx As Long, ByVal cy As Long, _
  ByVal fFlags As Long) As Long
 
Private Declare Function SendMessage Lib "User32" Alias _
  "SendMessageA" (ByVal hwnd As Long, _
  ByVal wMsg As Long, ByVal wParam As Long, _
  lParam As Any) As Long
 
Private Const BM_GETIMAGE = &HF6
Private Const BM_SETIMAGE = &HF7
 
Private Sub Form_Load()
  <font color=green>' Fenster-Handle der Taskbar</font>
  hwndTaskbar = FindWindowEx(0, 0, "Shell_TrayWnd", 0&)
 
  <font color=green>' Fenster-Handle des StartButtons</font>
  hwndStartButton = FindWindowEx(hwndTaskbar, 0, _
    "BUTTON", 0&)
 
  <font color=green>' Original-Bitmap lesen</font>
  hbmpOriginal = SendMessage(hwndStartButton, _
    BM_GETIMAGE, 0, ByVal 0&)
End Sub

<font color=green>' Neues Bild zuordnen</font>
Private Sub Command1_Click()
  Dim hbmpNew As Long
  Dim strFilename As String
 
  <font color=green>' Dateiname des neuen Bitmaps</font>
  strFilename = "c:	est.bmp"
 
  <font color=green>' Neues Bitmap laden</font>
  hbmpNew = LoadImage(0&, strFilename, 0, 0, 0, _
    &H0 Or &H10 Or &H40)
 
  <font color=green>' Neues Bitmap zuweisen</font>
  SendMessage hwndStartButton, BM_SETIMAGE, 0, _
    ByVal hbmpNew
End Sub

<font color=green>' Alten Button wiederherstellen</font>
Private Sub Command2_Click()
  SendMessage hwndStartButton, BM_SETIMAGE, 0, _
    ByVal hbmpOriginal
End Sub</code>