After testing some solutions, I tested a "sudo modprobe acpi" and got the message attached to this post. Any hint ?
** Attachment added: ""sudo modprobe acpi" error" http://librarian.launchpad.net/5493686/acpi_cpufreq -- kernel can't scale cpu frequency https://launchpad.net/bugs/36014 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
