How to Boot a Computer from a CD Sometimes you need to boot from a CD in order to fix or upgrade your computer. The problem is, most computers are set to boot from the hard disk, without trying to boot from a CD. Getting your computer to do this can be convoluted, so follow these steps to make sure that you boot correctly. This is also a helpful site http://www.wikihow.com/Boot-a-Computer-from-a-CD