You will be able to install Windows XP after that because the Basic Input/Output System (BIOS) that loads when you turn on the computer can read the cd and start the setup.
In case you don't about it what happens when you turn on the computer is that the Basic Input/Output Sytem (BIOS) loads and takes care of basic setup of hardware like hard drives, cd/dvd drives and keyboards and then it passes control over to an OS like Windows XP.
You don't need to use Boot and Nuke though as you can just boot format the drive within the Windows XP setup.
You just need to tell the BIOS to boot from the Windows XP cd instead of the hard drive first.
The Boot and Nuke is overkill for removing Windows XP. Boot and Nuke's main purpose is to make all the data is totally gone from the drive to remove senitive information like bank information and such.
As for installing Windows XP, if you are attempting to install it on computer that come with Vista I would recommend following the steps at http://www.howtogeek.com/howto.....-computer/ to install Windows XP along side side Windows Vista as there can be problems with putting XP on a machine that came with Vista so you will want Vista around just in case.