I’d wager that there are a huge number of Windows users who would probably be quite happy with Ubuntu Linux as their day-in day-out OS of choice. If only there were an easy way to try Ubuntu out on your windows machine without breaking anything, repartitioning or dealing with the diminished performance of a Live CD.
You’re in luck. Wubi takes the hassle out of installing Ubuntu on a loopback file system located on your Windows partition, while making it bootable just like a real-deal Ubuntu install. In fact, it _is_ a real-deal Ubuntu install, albeit in a slightly unconventional manner. If you go glassy eyed at the word “loopback”, don’t worry.. it’s just a fancy way of saying that your whole Ubuntu install is self-contained and stored in a single large file on your Windows drive.
source [downloadsquad]