Installing from within Windows
Another way to install Ubuntu is to use Ubuntu Windows Installer, or Wubi. This is perhaps the easiest of all methods. Go to www.ubuntu.com/getubuntu/download-wubi and download the program and run it within Windows. Then answer the questions that come up and wait. The process can take a long time because it will download the entire installation .iso, but once finished, a dialog box will appear telling you that you need to reboot. When you do, you will find that you will boot to a menu giving you the option to boot into either Windows or Ubuntu. More detailed information is available at the link above.