Zelda Majora's Mask Save File lost

[BlueThunder]

When I played the game yesterday everything was fine and i got to the Great Bay Temple and saved my game by pressing F5. I did not save it like on a n64.
Today I wanted to resume my game but the save file was deleted and not only that the save files of all the other games are also gone.
Does anyone know why this happened or if there is a way to get back my save file?
I'm using Windows 7 Ultimate

if there is no way to get it back can someone give a save file which is in or near the great bay temple?