My French is more than a little rusty but thanks to Google Translate, the message reads "Your Internet security settings have prevented the opening of one or of several individual files."
Were you doing any updates or adding programs before this all happened?
Although there may be a chance there's malware on the machine, my first suggestion would be to attempt a system restore and take it back to the most recent save. Do you need help walking you through this? What version of Windows are you running?
"An ounce of prevention is worth a pound of cure" ~ Ben Franklin