Recommended: 
Some days back we mentioned about how to Install Ubuntu in Windows, and now if you want to test the Ubuntu on your Windows System without installation so now its Possible with Portable Ubuntu for Windows. This system is built with the Colinux Kernel, Xming X server and Pulseaudio server for Windows. Portable Ubuntu for Windows is a useful tool when you need to move yourself to other machine that have Windows as operating system.
IF you want to try the Ubuntu on Windows PC, Download the portable ubuntu here. It comes as a 438 Megabyte self extracting executable. Users can then immediately start Ubuntu in Windows by clicking on the run_portable_ubuntu.bat file that is located in the root directory of the software program. Its Totally free and Runs Smoothly on Windows Machine.
Download the portable ubuntu here via [ghacks]
you guys are great