How to force ACPI in Ubuntu 11.04

This is a quick 'how to' guide to force ACPI within Ubuntu 11.04

As root:

cd /etc/default/

nano grub

Find the line that contains:

GRUB_CMDLINE_LINUX=""

And modify it to read:

GRUB_CMDLINE_LINUX="ACPI=FORCE"

Save out the changes and (still as root) run:

update-grub