Boot from a Live CD
Boot from a Live CD
To boot from any CD (Including LiveCDs), you must make sure that your BIOS bootup settings allow this. This is usually changed from the BIOS setup menu. The BIOS bootup menu is usually accessed during the first few seconds after powering on your computer.
The BIOS setup access key is often displayed on your screen (often it is the F2, Delete, or F10 key), depending on your BIOS. Further, most recent BIOS's allow a one-time choice of the bootup medium, so that either a CD or USB can be chosen as the bootup medium on a one-time basis (without changing the regular BIOS settings).
If the BIOS on your computer does not allow a one-time bootup-medium choice and you must change the regular BIOS settings temporarily, then enter the BIOS setup menu and hunt around for the settings for Bootup device priority (sometimes in the Advanced Setup menu). Make sure your CD/DVD optical drive is listed as the first boot device, before the hard drive.
If you intend to use a LiveUSB installation instead of a LiveCD, then set the boot order so that the USB drive is listed first, before the hard drive. (Obviously, your BIOS must allow booting from a USB drive for this option to be available.)
Once you have installed all your operating systems from the LiveCDs or LiveUSBs (or finished using other bootable LiveCDs or LiveUSBs such as GParted), you can reset the first bootup device to be the hard drive again.
After installation, most security experts then recommend restricting bootup to the hard drive only. A BIOS password should also be created so that the BIOS bootup settings cannot be changed by a casual passerby. In this manner a casual passerby will not be able to boot their own LiveCD or LiveUSB onto your computer (and thereby potentially change your computer without your permission).
If your computer, device, or hardware uses UEFI instead of a BIOS bootup system, then see this page.
If your computer, device, or hardware uses Coreboot instead of a BIOS bootup system, then see this page.