hit the auto adjust on your monitor.
if that doesnt work you may have selected a resolution larger than the monitor supports. Change the resolution to a supported one.
if you can pan around to all the areas of the screen then you might have expanded your desktop or enabled a virtual desktop. This would be GPU dependant.
Sorry if I was not clear. I am running XP and i tried all of the resolutions to no avail. When I open either Word or Outlook, the first display shows the Word icon very wide instead of square and the same with Outlook. My icons in the tray are widened and so are the ones in the quick open on the left. Some emails are ok but others put some of the ends of the sentences off the screen with no way to get the back. Fred