Hello sarge, if you have the XP setup CD you can boot from this CD and attempt either the repair install option; press F8 to agree to the license terms select the repair option.
Or use the recovery console with the XP CD and type: 'fixboot [drive
]' and 'fixmbr [drive
To setup without the CD would be impossible without the i386 folder taken from an XP CD and put onto the HDD you want to install on.
It could be possible to use a start-up disk to access the HDD if you had problems booting the operating system. Then you would have to initiate the setup program.
Take a look at the tutorial posted by William William on how to install without a floppy or CD this should explain how it works. http://www.syschat.com/install-windo...py-cd-463.html
You could use you CD to setup XP on your other PC, however unless you have purchased a license from Microsoft which allows you to use it on more than one computer, you would be unable to receive certain support for your system as the OS is already registered to the other computer and you would not be able to validate it.