Now you have a Ubuntu image on your PC, you need to get it onto a CD.
If you do not have software to burn an ISO image, download Infra Recorder, an open source image burning software.
Insert a blank CD-R, if a dialog box pops up - click Cancel.
Open Infra Recorder, and select the
→ .Select the Ubuntu CD image file you want to use, then click Open.
In the dialog box that opens, click OK.
To burn most ISOs, you can use Apple's Disk Utility (Disk Copy in older versions).
Launch Disk Utility
→ →Drag the ISO to the sidebar of the Disk Utility main window.
Select the ISO where you just dragged it, and select
→ →In Disk Utility, ensure that the Verify burn checkbox is ticked. You may need to click on the disclosure triangle to see the checkbox.
Insert a blank CD and select Burn
Check that the verification was successful. If the verification was unsuccessful, make sure that a sample of the directories on the CD can be accessed by the finder.