Form position missing when diffrent screen size

I'm using manual position at screen 1280x1024 on right down corner, compile then try to another PC run 1024x784, the form gone,
there have code to lock it? any screen size, Form still right down corner

i now making game anti hack, :D

A begining;

Private Sub Form_Load()

Top = Screen.Height - Height
Left = Screen.Width - Width

End Sub