Ensure you get an XP FPP install cd slipstreamed with SP3.
Download and run intel's INF update utility http://downloadcenter.intel.com/Detail_ ... hipset+inf
Go to Control Panel -> System -> Device Manager -> IDE controllers then in Properties change any specific branded drivers listed to "Standard Dual Channel PCI IDE Controller".
If the old system drives were on SATA and the new system's SATA controllers are off-board and/or non-Intel then you may further problems. Try to choose a new system with an Intel chipset generation no higher than D945/D946 as much as possible. Check the BIOS on the newer system to see if can at least recognize the old drive or its clone.
Then as previously suggested, boot the XP install disc on the new PC and do a repair of the C: partition. Afterwards, run intel's INF update utility again, reboot, then download and apply the latest Intel LAN, video, and audio drivers for your new system. You may be forced to call MS Genuine Advantage on their automated support line given the huge changes between systems.
Other than these procedures, you'd have to learn to work with Microsoft SysPrep.