If your computer suffers damage like a boot sector virus or corrupted operating system, it needs to be rebooted. Back up all you data in a back up device or service. Turn on your computer put the restore CD into the CD or DVD drive. Allow the computer to boot and follow the prompts to restore your computer to its original settings. Click through the warnings showing that your hard drive is about to be formatted. When the process is complete reinstall your programs and it's as good as new.