G/Day

I just did the Latest "Auto update" of Calibre and I now find that all my books in my Calibre Library have gone? Am I the only one this has happened too? Have I done something wrong" all I did was click on Install the update for Windows Xp3 and then it seemed to be reinstalling the whole Calibre program not just an Update. It also added a new Shortcut on my Desktop? Can someone tell me what is happening Please, Dasha