as long as you have an OEM OS (full version of your operating system, most likely Windows XP) you would use THAT as your recovery disk. to format using Windows XP, you just put the cd in your cd drive and if your current windows installation is operable, just click NEW INSTALLATION in the drop down menu that appears. if your current windows installation is inoperable, then put your windows xp disk in the cd drive and reboot then READ and follow instructions. most computers will boot from the cd drive before the harddrive. IF IT DOES NOT boot from the cd and goes straight to your old installation of windows then you will have to enter bios on your next restart and tell the computer which device you want the computer to boot from 1st. you can enter bios a number of ways on bootup, it depends on the motherboard. usually its the <delete> key but it could be F1, F3, F5, F8 or the left <CTRL> key. you'll just have to keep rebooting untill you find the correct key or visit your motherboard manufacturer's website for support on that. once u figure that out make the computer boot from the CDDRIVE 1st. then reboot with windows xp in the CDDRIVE.