"Unlike UNetbootin, which installs Linux on a hard disk partition, Wubi works by installing Ubuntu within a file stored on your Windows drive, and adding itself to the Windows boot.ini file to allow you to choose between Windows and Linux at boot time.
"Wubi is based on Ubuntu 8.04 Long Term Support (LTS), which was released in April 2008. Both Wubi and Ubuntu 8.04 are available now in stable beta versions.
"You can install Wubi by downloading Ubuntu 8.04, burning it to a CD-ROM, and running the installer included on disc, or you can download the 10MB Wubi installer and run it. That approach may be a little slower, as Wubi has to download the installation files it needs over the Internet, rather than from a local CD image."
