So far, I only have one method for you knowing that you have a XP Pro disk.
1.Try booting from the XP Pro installation disk.
2.Once you get there, you'll see an option to repair/recover, which would most likely be the R key.
3.It'll then ask "What windows installation would you like to log onto?" Usually you would just put in the number 1 for that, then press enter
4.If needed, type in the password,
5.From that point, type in fixmbr, then fixboot.
There's my two cents.
Also, if you're having issues booting with the CD, have you tried accessing the bios and making the first boot priority the CD/DVD drive?