I decided to upgrade my FC installation to the latest version - FC itself offered the upgrade when I turned the machine on, so it appeared that it was nicely packaged to make the upgrade easy.
After a long download of packages, the machine rebooted and then started taking me through configuration options (timezone, disks to use for the installation etc) but then it crashed trying to write to disk and now leaves me at a grub prompt whenever I boot.
Is there any way to "get at" the installation files and get back into trying to install or do I now need to download an ISO and burn a DVD and start all over again?