access 2007 form "switchboard"

I have created a switchboard form with an image located in the centre of the foem & set as such! The centre of the image as a blank rectangular area which I have placed serveral command buttons & below this an explanation text box. However if I load this database on a machine that has a 17inch monitor as apposed a 19inch monitor the command buttons & text box are slightly displaced to one side of their original placement!
How can i keep them in the original positions regardless of monitor size or resolutions?