OK so i went into a professionnal to repair it and since all the recovery system of windows 10 was broken (apparently since the second reboot) and since windows 8 (the original software from factury)...

Thank you again your quick answer.

The thing is, as i said i don't have any cd installation i just have an usb key where i can maybe download what you mention.

So where can i find this bios...

Hello guys,

First of all i would like to apology for my english wich won't be good i think since i am French and not English speaking native.

My Laptop is Dell Inspiron 7720 and i had Windows...