Images cannot go on an MDIForm. Only objects with an align property may go on them. But with a picture, you can. Place a picture on the MDIForm, make the picture box the same size as the MDIForm. You can use this code to keep the picture the same size (incase the MDIForm is resized).
Code:
Private Sub MDIForm_Resize()
On Error Resume Next
Picture1.Width = Me.Width - 400
Picture1.Height = Me.Height - 400
End Sub
and put an image on top of that picture and load the picture you want to use. Place that picture in the center.