The operating system on your computer can become corrupted and unusable. This can be caused by malicious software like viruses or harmful scripts that invade your computer while you are browsing the internet, or by individuals who have hacked into your computer to steal your information. A recovery CD can be a valuable tool to restore functionality to your computer should the operating system become corrupted.

Creating the Recovery CD

When you purchase a new computer or install a new operating system, you will usually be prompted to create a backup or recovery disc. Simply follow the instructions to do so. If you are not prompted, press the "F1" key while looking at your desktop and search for "recovery CD" to find instructions to make one.

When to Use the Recovery CD

Use your recovery CD if your computer stops booting properly or begins working so slowly that you cannot use it for much. These are signs that damage has been done to your operating system.

Booting from the Recovery CD

Having the recovery CD inserted in your CD-ROM drive during startup is usually enough for your computer to recognize it and present you with recovery options. If it does not, you may have to change the boot sequence in your BIOS.

When to Change the BIOS

To access your motherboard's BIOS, look for an instruction during startup that says something like, "Press F3 to enter setup." Once in the BIOS, you will find an area where you can change the boot sequence so that the computer will boot from the CD-ROM.

Recovery Instructions

When the computer boots from the CD-ROM it will present you with instructions to recover your operating system. Simply follow the instructions to restore your computer's functionality.

Source:

Disk Internals.com: Restore Your PC by Booting from a Recovery CD