Minimum system requirements
To install or try Xubuntu within the Desktop/Live DVD, you need 256 MB of memory, if you are using the Minimal CD, which uses the non-graphical Debian Installer and downloads packages as you install, you need 128 MB of memory.
Once installed, you should have at least 512 MB of memory.
When you install Xubuntu from the Desktop CD, you need 6.1 GB of free space on your hard disk. The Minimal CD requires you to have 2 GB of free space on your hard disk.
Recommended system resources
To get a smooth experience when running multiple applications parallel on the desktop, it is recommended to have at least 1 GB of memory.
It is recommended to have at least 20 GB of free space. This allows new application installations as well as saving your personal data on the hard disk in addition to the core system.
Minimum system requirements for Xubuntu 12.04
To install and run the Xubuntu 12.04 release, it is strongly recommended to have at least 512 MB of memory. Installing with the alternate or Minimal CD requires you to have only 128 MB of memory.
You need 4.4 GB of free space on your hard disk. If installing with the alternate or Minimal CD, you will need 2 GB of free space.