How to Install Ubuntu Without a CDby Paul Nelson
Ubuntu is an open-source Linux-based operating system which is provided free of charge. Two separate versions of Ubuntu are offered: one for desktop computers and the other for netbooks. Ubuntu can run entirely from a USB drive without accessing the user's main hard drive. Ubuntu is also installable from a USB drive onto the hard drive to allow access to the operating system without booting from a USB drive.
Download the Universal USB Installer from Pendrivelinux.com.
Open the Universal USB Installer program by double-clicking on the downloaded file.
Read the license agreement and then click "I Agree."
Select from the drop-down list the version of Ubuntu that corresponds with the version you intend to install.
Check the "Download the ISO" box if you do not have the Ubuntu installation already downloaded. If you already have a copy of the Ubuntu installation, click the "Browse" button and select the Ubuntu image.
Insert a USB flash drive into the computer.
Select the USB flash drive letter from the drop-down box on the "Universal USB Installer" window. This drive letter is the same as the letter given for the drive in "My Computer."
Click "Create" to create a bootable USB Ubuntu installation.
Install Ubuntu by inserting the USB drive into the computer and then turning it on. This causes the computer to boot from the USB drive and the Ubuntu installer to display.