Thanks for the answer. I open the .msstyle file with ResHack, and there is a lot a bitmaps! I changed the ones looking like the classic Start button with the Vista one, but it doen't work, the .msstyle become buggy too. I think, as you've said, that there is more than bitmaps to change. Maybe someone will help. I heard that StyleBuiler may help... Is it only useful in creating new themes or to modify existing ones?