root user login denied

Hi there,

Boot on a live Linux distro (with CD or usb) and mount your hard drive :

mkdir /mnt/hdd
mount /dev/sda3 /mnt/hdd
mkdir /mnt/hdd/boot
mount /dev/sda1 /mnt/hdd/boot
chroot /mnt/gentoo /bin/bash
source /etc/profile
export PS1="(chroot) $PS1"

Once that executed, you will be able to got a shell with a real environement, meaning that in case you run a Live Linux distro based on debian (ubuntu live for example) but your disto is Fedora, you will be able to yum or any other stuff of fedora.

Of course, you have to replace sda3 / sda1 by your own partition (try a fdisk /dev/sda then input the letter p for look your partition list)

In my Example, sda1 is the boot partition and sda3 the root one.