These [hidden] folders you are referring to ( i.e.; folders within the
Windows directory with names like: $NtUninstallKB980218$ ), are just the
UNINSTALL part of the update - that is; your original files that would be
replaced in the event you were to uninstall a specific update.
If you used these files in an effort to update your new XP installation,
you would probably be replacing system files with identical ones. Also,
the proper install procedure would not be followed, so even if you had the
correct update files to hand, registration of them would be needed and
copies placed into the ServicePackFiles and dllcache folders...
Cheers, Tim Meddick, Peckham, London. :-)