Update on my problem:
I found that my original SD Card should be corrupted.
So, I bought a new one (class 10, 16Go) and burned the image sent by davidfor.
After a lot of time I finally managed to launch the restore process with the new SD installed but my reader is now stuck on the restoring page. At the time I'm wrinting this the reader is displaying "restoring" with the black and white dots moving for more than 30 minutes

Is it usual?