I have been using this computer for a long time and really rely on it for many projects. One day it just would not start up saying Windows could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SYSTEM.
Also says I can attempt to repair by using the original Setup CD-ROM.
As Mark has said, Windows XP is no longer supported and software solutions to repair XP are as rare as the pope's poop. Windows system 32 config is a major component of the operating system and the only way to repair it is to have the original back-up disk, any other will not work.