Before you reformat, backup your drivers. A good program which I personally use is [url=http://katz.cd/search/driver+magician]Driver Magician[/url]. After that, backup your documents or any important documents that you wish to keep. Now you're ready... insert your OS Installer then reboot your pc.... if your pc can automatically boot the CD, a message like "Press any key to boot from cd..." will appear... if not, you may have to change the boot sequence to CD ROM as primary boot device in the BIOS settings.... Am I sounding too technical? If so I suggest you consult a technician to do it for you... otherwise lets continue..... once you've booted the cd, from there, its pretty much easier, follow on screen instructions (READ CAREFULLY & PROPERLY).... there... the basic idea is to boot your CD actually....