Private Sub Form_Load()
Timer1.Interval=10
Timer1.Enabled=True
End Sub
 
Private Sub Timer1_Timer()
If Me.Top < 0 Then Me.Top = 0
If Me.Left < 0 Then Me.Left = 0
If Me.Top > Screen.Height - Me.Height Then Me.Top = Screen.Height - Me.Height
If Me.Left > Screen.Width - Me.Width Then Me.Left = Screen.Width - Me.Width 
End Sub