Do you have a missing ntldr error when starting xp?
Are you in recovery console and want to copy from Win cd to c:\ but can't find the files?
I don't know if there is a backup of the files in Windows ( maybe Dll cache, Repair, Service pack files folders?)
But it should be on your CD in I386 folder. I think it's archived and it has another extension. You need the expand command at the recovery console, then replace the files.