what card do you have? are the drivers up to date?
You can get the latest drivers from amd's site
http://support.amd.com/en-us/download
the auto-detect should work just fine...
edit also what's the monitor? some have 'fake' bezels so the panel itself doesn't extend all the way to the outer edge, only the glass on top of the panel does, so it looks a bit silly...
edit2 you can change it into advanced view from the preferences....