If the BIOS date in your computer is earlier than 1998, your computer may not give you the option to boot off of a CD rather than a hard drive. In this case, you won’t be able to boot directly to the CD. But if its after that here are the instructions:
To set your computer BIOS to boot from a CD
1. Restart your computer. Watch the start-up instructions that are displayed on-screen.
A message will be displayed instructing you to press a named key (often F2, F12, or Delete) to go into settings/setup/configuration. (The key and the message will vary according to the type of computer that you are running.)
Press this key to enter the BIOS setup mode.
(If your computer is particularly fast, it may remove the message before you have the chance to press the key; in this case, try pressing the key once a second, starting the moment you reboot.)
* On a Dell computer, you should hit F2 to enter the BIOS.
* Other computers may require you to hit the DEL (Delete) button to enter the BIOS.
* On newer computers, you may be able to hit F12 to select a temporary boot device rather than changing the permanent boot sequence in the BIOS itself. If your computer offers this option, simply select the CD or DVD drive containing the antivirus CD as your temporary boot device, and skip steps 2 and 3.
2. In the BIOS window, find the area that controls the boot sequence and rearrange the list of devices so that your CD or DVD drive is checked before your hard drive.
For most situations, a suitable sequence is:
1. A (Floppy)
2. CDROM (or DVDROM)
3. HD1 (or C).
If your drives are listed in this order, then when you keep the Linux CD or DVD drive during a reboot, it will boot right to it! FTW!
You’ll need to go into the system bios (usually by pressing F1 directly after turning the machine one) and tell it that you need to boot from the CD/DVD drive before booting from the hard drive.