1)Reboot your pc, after bios messages, when you see the Grub row and then press ESC key
2) Select the kernel row and press edit select
3) Select the "kernel /boot/......" row and press "e" to edit this row
4) add the acpi=force parameter at the end of the row
5) then press "enter" and then press "b" to boot
6)重新启动进入后 ，用 sudo gedit /boot/grub/menu.lst
找到 # defoptions=nosplash ，去掉注释，使之生效，并在本行最后，加上 acpi=force parameter
7)存盘退出
8）update Grub type
sudo update-grub
9）再用shutdown -h now 试试。
