Public Class Form1
    Private Declare Function RegisterHotKey Lib "user32" (ByVal hWnd As IntPtr, _
      ByVal id As Integer, ByVal fsModifier As Integer, ByVal vk As Integer) As _
      Integer
    Private Declare Sub UnregisterHotKey Lib "user32" (ByVal hWnd As IntPtr, _
    ByVal id As Integer)
    Private Const Key_NONE As Integer = &H0
    Private Const Key_ALT As Integer = &H1
    Private Const Key_CONTROL As Integer = &H2
    Private Const Key_SHIFT As Integer = &H4
    Private Const Key_WIN As Integer = &H8
    Private Const WM_HOTKEY As Integer = &H312
    Protected Overrides Sub WndProc(ByRef m As Message)
        If m.Msg = WM_HOTKEY Then
            Me.Show()
            UnregisterHotKey(Me.Handle, 1)
        End If
        MyBase.WndProc(m)
    End Sub
    Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As _
    System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        If MessageBox.Show("Form verstecken?", "Programm beenden oder" & _
          "verstecken?", _
          MessageBoxButtons.YesNo) = Windows.Forms.DialogResult.Yes Then
            RegisterHotKey(Me.Handle, 1, Key_ALT Or Key_CONTROL, Keys.F1)
            Me.Hide()
            e.Cancel = True
        End If
    End Sub
End Class