Burn your CD or create a USB drive,Windows

Windows

1. Insert a USB stick with at least 2GB of free space
2. Download the Universal USB Installer
3. Click 'Run' when prompted

4. If the security dialog appears, confirm by clicking 'Run'

5. Read the licence agreement and choose 'I Agree' to continue

6. Select Ubuntu Desktop Edition from the dropdown list

7. Click 'Browse' and open the downloaded ISO file

8. Choose the USB drive and click 'Create'

Mac

We would encourage Mac users to download Ubuntu Desktop Edition by burning a CD for the time being. But if you would prefer to use a USB, please follow the instructions below.

Note: this procedure requires an .img file that you will be required to create from the .iso file you download.

TIP: Drag and Drop a file from Finder to Terminal to 'paste' the full path without typing and risking type errors.

1. Download the desired file
2. Open the Terminal (in /Applications/Utilities/ or query Terminal in Spotlight)
3. Convert the .iso file to .img using the convert option of hdiutil (e.g., hdiutil convert -format UDRW -o ~/path/to/target.img ~/path/to/ubuntu.iso)
4. Note: OS X tends to put the .dmg ending on the output file automatically.
5. Run diskutil list to get the current list of devices
6. Insert your flash media
7. Run diskutil list again and determine the device node assigned to your flash media (e.g. /dev/disk2)
8. Run diskutil unmountDisk /dev/diskN (replace N with the disk number from the last command; in the previous example, N would be 2)
9. Execute sudo dd if=/path/to/downloaded.img of=/dev/rdiskN bs=1m (replace /path/to/downloaded.img with the path where the image file is located; for example, ./ubuntu.img or ./ubuntu.dmg).
10. • Using /dev/rdisk instead of /dev/disk may be faster.
    • If you see the error dd: Invalid number '1m', you are using GNU dd. Use the same command but replace bs=1m with bs=1M.
    • If you see the error dd: /dev/diskN: Resource busy, make sure the disk is not in use. Start the 'Disk Utility.app' and unmount (don't eject) the drive.
11. Run diskutil eject/dev/diskN and remove your flash media when the command completes
12. Restart your Mac and press alt while the Mac is restarting to choose the USB-Stick

Ubuntu

1. Insert a USB stick with at least 2GB of free space
2. In the main menu, go to System > Administration and open 'Startup Disk Creator'

3. Click 'Other' to choose the downloaded ISO file

4. Select the file and click 'Open'

5. Select the USB stick in the bottom box and click 'Make Startup Disk'
6. That's it! When the process completes, you'll be ready to restart your computer and begin installing Ubuntu.

Copy and paste form: http://www.ubuntu.com/desktop/get-ubuntu/download