It never happened before :
all the system restore points disappeared, every bookmark opened in different commercial links, every browser search returned to the first empty page
all my cleaning and back up applications unloaded just after the launch and the exes in their folders were not more the same .
I tried the safe mode and to restore from the original disk but nothing changed
I was only able to manually copy my data to an external drive, only few at the time
then after the first reformat I had only 1 resolution (800x600) so huge that the DriverMax buttons were out of the desktop !
I went on with the second reformat and it was ok ...
but I don't' even know and yes I would really like to know the name of that very big ...hole !