|First thing you need is a Network Interface Card with a boot ROM installed. Network Interface Cards don't normally come with boot ROM installed, you have to obtain them separately. This allows the computer to boot from a central server.|
You then need a server that will boot a workstation. I am not sure that Windows XP ill do remote booting, you may need something like Windows Server 2003 to do that with the necessary licences for each workstation you wish to boot.
Diskless workstation are not something you would normally use in a home network as they would only be used in large installations where centralised administration is made simpler.