Hi REdWolf,

Thanks for the advices. Indeed, the laptop is used for IT developpement, and may need Java.
I’m not able to work on it until next Monday, but I’ll try the Rufus track (I have another laptop nearly the same than the one that crashes, so I hope I could create a repair from it).
We’re using firefox and “addblock”. I suspect the user of the laptop to do not have reboot for a long time… and therefore, some of the security updates (windows, avast) have probably not been set at time.

I update the thread on Monday, to tell if the Rufus method has worked. Otherwise… I’ll copy the critical data using the DOS to an usb (10 minutes of work ;)) and reformat the laptop.
Thanks again,
tihitibo