I've got Xubuntu (live disc) it starts and loads to the desktop no
problem.

It starts to install no problem, I have got to the partitioning bit
and have got stuck, I've partitioned 10gb for the installation, and
just under 1gb for swap, but it says I have 'No root file system is
defined' 'Please correct this from the partitioning menu', I have
tried and am looking on the 'net but have not sorted it yet, does
anyone now how to do it, I am so close now.......