Phone stuck on Restarting

Hello,

The issue doesn't concern my computer but my mother's, which has been stuck for two days on the blue screen saying Restarting.... (A Compaq laptop running Windows 8).
It all started when there was an internet connection problem and we called the provider "Orange". The lady asked us to restart the computer and that’s when disaster struck; it got stuck on that infamous blue screen. She suggested sending someone to repair it for 115 euros, but it's less than a year old and still under warranty. Besides, she bought it from Conforama and I have serious doubts about their customer service. Anyway, could someone advise me on what to tell her because she has tried letting it completely discharge before turning it back on (I know, that's very bad), but the blue screen with "Restarting..." is still there.

Thank you in advance for all your advice.

P.S.: While browsing the forum, I read quite a bit about pressing F10, pressing Alt + F10 at the same time; pressing Ctrl + Alt + Esc at the same time. If you have any opinions on this subject, I would be interested.

Best regards.

Valérie.