Thank you for your answers, but, eugen-b, I searched mhwd-tui on the forum, but I did not found anything that helped me with the installation. I tried some things I saw on some posts, but nothing resolved my problem. Could you provide me more details, maybe I missed something?
And gionno, thank you but I don’t care very much if my computer is still on Windows 8.1, I don’t especially want to upgrade it to 10, I use it only for playing, and I don’t think it could help me to install Manjaro.
EDIT : I tried to boot with the free drivers, but same results. I tried to install Manjaro on a virtual machine, and it worked.