Is it an upgrade version? Are you actually upgrading with an older version installed or from a clean HD? Did you boot from the CD?
I used the upgrade version of XP Pro 32 on a new HD, but as I recall, there is a certain way you have to do that, like executing a WinNT.exe file in a certain directory on the CD. Using the right one allows it to copy a lot of your files to the HD, instead of expecting a previous installation to be there.
My memory is very fuzzy on this, because I did it over 2 years ago. So, answer my first questions and I will look into it if need be.