Ubunutu Live!- Boot from Disc it will boot and ask if you just want to try and it won't install anything. It runs off RAM and your CDROM.
Download | Ubuntu
Try Ubuntu before you install it.
1. If you're using a CD:
Put the Ubuntu CD into the CD/DVD-drive and restart the computer. You should see a welcome screen prompting you to choose your language and giving you the option to install Ubuntu or try it from the CD.
If you don't get this menu, read the booting From the CD
guide for more information.
2. If you're using a USB drive:
Most newer computers can boot from USB. You should see a welcome screen prompting you to choose your language and giving you the option to install Ubuntu or try it from the CD.
If your computer does not automatically do so, you might need to edit the BIOS settings. Restart your computer, and watch for a message telling you which key to press to enter the BIOS setup. It will usually be one of F1, F2, DEL, ESC or F10. Press this key while your computer is booting to edit your BIOS settings.
You need to edit the Boot Order. Depending on your computer, and how your USB key was formatted, you should see an entry for 'removable drive' or 'USB media'. Move this to the top of the list to force the computer to attempt to boot from USB before booting from the hard disk. Save your changes and continue.
3. Choose your preferred language and click on 'Try Ubuntu 10.04'
4. Your live CD desktop should appear. Have a look around!
5. When you are ready to install Ubuntu click on the icon on your desktop: 'Install Ubuntu 10.04'