Hello nukecad,
thank you for taking so much trouble to answer me, your answer is very complete and documented !
I started the pc in safe mode, to prevent a game or an application from launching, the result is the same ... I think I'll give up, these cookies are ultimately harmless!
Thank you very much for answering me and explaining the origin of the problem.
You can close this thread.
I'll drink a beer to your health :-)
Best regards.
Eric, from Brittany, France.