Has you cd/dvd drive letter changed since you installed XP?
Here is a copy of a post on the web from 2003:
The problem appears to be due to the following situation. After installing
XP, I changed the drive assignment for the DVD-ROM. XP keeps the old
assignment in the registry as expected. When I later tried to install IIS,
it uses the old assignment as expected. The installer then says it is
looking for D:\i386\_vti_inf.htm but there is no \i386\_vti_inf.htm on the
CD. The trick is to just say G:\i386 to the Installer and not look for
G:\i386\_vti_inf.htm. The Installer stupidly continues to look for other
files on D:\i386 so you have to change it to G:\i386 multiple times.