Maybe if we had an idea as to what is "messed up" with respect to your "desktop" we might be able to make some simple suggestions as to how to recover.
Are you just talking about icons that are missing, or items from your start menu?
Do you have a sense of what you did or were doing when it got "messed up".
You could always use the native "Reset" function but that might represent a loss of programs and data. Some people have not had good luck with the reset function.
Even a system restore, might help, although for the most part, that just deals with registry entries and system files and drivers.
As far as I know, there is no magic button to press that will return things to a particular state, or a particular point in time unless you have a disk image or something similar