That file is part of the installation instruction Windows use during installation . If your XP cd is scratched/smudged the cdrom can't read it because the file has to be on a genuine Micrsoft disk .
However if you are using a privately compiled installation disk then it was not put together correctly.
Which kind of CD/Media are you using.
You have another post concerning your installl problems . You should really continue with just one post for issues concerning your original problem.You will get better help quicker as the guys will be able to follow your saga in one Thread.