Desktop And Mail Gone


This is crazy - I have a G4 running OS X (10.3.9) - I am the only user of the computer, so there is only 1 account setup on it. I turner it on yesterday, and everything I had saved on the desktop was gone, all the settings were reset to default, and all my mail account settings were gone, along with all of the emails I had. It is as if my logon account profile had been wiped and reset to the way it was the first time the computer was turned on. All of my installed software is fine, as well as all my files (that were not saved on the desktop). Have you ever heard of this? Is there any way of getting any of the files back that were there - or the email?? I have searched the hard drive for the file names and they are no where to be found.....