jef_m wrote:

> Hi again,
>
> I'll have to reinstall my Gentoo . I've already downloades stage3 and
> portage from a mirror . I have no gentoo live or install CD , do I have to
> get one, or can I install from my running ubuntu, and chroot to the gentoo
> system to install it as I would do with a CD?

You can use any livecd to install Gentoo. Just boot the computer with your
preferred livecd (eg, ubuntu, knoppix) and follow the instructions in the
Gentoo handbook. You won't be able to use stages from the CD as you would
if you used a Gentoo livecd, but this doesn't matter as you can download
everything from Internet (if you haven't already).
You can also use an existing running distro, by chrooting into the partition
where you intend to install Gentoo.

See the following document, sections 3 and 5.

http://www.gentoo.org/doc/en/altinstall.xml