Public Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" _
(ByVal hwnd As Long, ByVal nIndex As Long) As Long

Public Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" _
(ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Public Const GWL_EXSTYLE = (-20)
Public Const WS_EX_APPWINDOW = &H40000

Private Sub chkTaskbar_Click()
Dim style As Long
Hide
style = GetWindowLong(hwnd, GWL_EXSTYLE)

If chkTaskbar.Value = 0 Then

If style And WS_EX_APPWINDOW Then
style = style - WS_EX_APPWINDOW
End If
Else
style = style Or WS_EX_APPWINDOW
End If
SetWindowLong hwnd, GWL_EXSTYLE, style
App.TaskVisible = CBool(chkTaskbar.Value)
Show
End Sub