Private Declare Function ReleaseCapture Lib "user32" () As Integer
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" ( _
ByVal hwnd As Integer, _
ByVal wMsg As Integer, _
ByVal wParam As Integer, _
ByRef lParam As Object) As Integer
Private Const HTCAPTION As Short = 2
Private Const WM_NCLBUTTONDOWN As Short = &HA1S
Private Const WM_SYSCOMMAND As Short = &H112S

Private Sub Form1_MouseDown( _
ByVal eventSender As System.Object, _
ByVal eventArgs As System.Windows.Forms.MouseEventArgs) _
Handles Form1.MouseDown
        ReleaseCapture()
        SendMessage(Me.Handle.ToInt32, WM_NCLBUTTONDOWN, HTCAPTION, 0)
End Sub

Ich arbeite mit:
Windows 10 Professional 64-bit * Visual Basic 2010 Express