close it is F8, but it could also be the delete button or even the escape but more than likely it will be F8 but it can be any of those depending on what bios you have try F8 first when you switch your computer on after a few seconds as soon as you see the computer booting press F8 a few times it will get you into bios, yes go into your Bios and set the boot sequence to your cd rom drive to boot first, then make sure you save the settings and have the disc in the drive reboot and it should work. you could also make xp floppys boot discs you will need 6 spare floppys to do it though, that way you can install xp still without going into bios as more than likely your boot set up is floppy first so this would be better for you if you do not know how to go into bios.
http://support.microsoft.com/default...NoWebContent=1