I have an outdated version of Ubuntu. Can I back up my files, download the latest version to a disk & do a complete fresh install of the latest version? Or do I need to uninstall the outdated version first? Sorry I am a beginner in Linux & trying to learn :)
Installing directly over the old version is the most stable and easiest way to upgrade. You could use a backup program like Aptik to back up your added repos and program configuration files, then use the file manager to backup your personal files to an external drive or use a cloud storage program like Dropbox.
Just choose to install over your old Ubuntu when installing with the Live CD, and it'll overwrite over the old version. This is also works if you need to overwrite another Ubuntu based distro such as Lubuntu or Xubuntu.
Installing over the top is fine, just chose
Erase this disk and install or
Install over Ubuntu XX.xx. Make sure you have a backup and a list of programs.
However, you could upgrade it, preserving your documents etc, by running the command - Wouldn't work for version 10.04.
sudo update-manager -d