Q I have Ubuntu 7.04 installed in my laptop, and I would like to upgrade it to Ubuntu 8.10 that I have on a DVD. Is that possible? If yes, how can I proceed?
A The in-situ upgrades provided by the Update Manager are only recommended for stepping one release version at a time; 7.04 to 8.10 is a jump of three releases. The safest option is to re-install from the DVD. If you've followed the advice that is often given to use a separate home partition, you can reinstall the operating system without touching your personal data and settings in your home directory.
Even if you don't have a separate /home, Ubuntu has added a crafty trick to the 8.10 installer to preserve your home directory when reinstalling. Boot into the live disc's desktop and run the installer. When it reaches the partitioning section, select the Manual option. You can then set up your partitions as before, setting one for / with an ext3 filesystem and the other, smaller, partition as swap. If you have a Windows partition, leave this alone. The important point here is that you do not set the / partition to be formatted. You will be warned that the root partition is not marked for formatting. If you continue, the system directories, /etc, /bin, /usr and so on, will be deleted prior to installing the new release but
/home will be left alone.
As usual with any major operation like an OS upgrade, if you value the contents of your home directory, you should back them up first, but this is only a precaution; your existing installation should be replaced by Ubuntu 8.10 without touching your files.