Install Lubuntu 14.04.1 with nvidia drivers 331 while keeping Windows 8 on the side

1) Install Lubuntu 14.04.1 fresh using alternate image with RAID support.

Link to ISO image :

http://cdimage.ubuntu.com/lubuntu/releases/14.04/release/lubuntu-14.04.1-alternate-amd64.iso

2) After reboot :

sudo apt-get install nvidia-331 nvidia-prime

3) To add Windows 8 entry in grub, here is the magic recipe :

sudo vi /etc/default/grub

Replace :
GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
With :
GRUB_HIDDEN_TIMEOUT=10
GRUB_HIDDEN_TIMEOUT_QUIET=false

4) Search for the magic String !
This command :

sudo grub-probe --target=fs_uuid /boot/efi/EFI/Microsoft/Boot/bootmgfw.efi

will output a String like XXXX-XXXX, copy it and then create a custom menu entry for Windows 8.

sudo vi /etc/grub.d/40_custom and append these lines :

menuentry "Microsoft Windows_8" {
search --fs-uuid --no-floppy --set=root XXXX-XXXX
chainloader (${root})/EFI/Microsoft/Boot/bootmgfw.efi
}

5) Run sudo update-grub so that the menu entries gets regenerated

6) Reboot and enjoy !