24" White iMac

My 24" White iMac is as beautiful as ever.  I maxed out RAM (3GB) when it dropped in price and then some years ago found a good shop that replaced my nearly full HD with a 1.5 TB HD and it did well. That 1.5 TB HD is now near full so I bit the bullet and bought a 3TB HD and took it in for replacement. The shop recommended adding a small OWC SSD in place of the optic drive to speed it up.

Sadly, once apart they discovered that the logic board would work with an SSD in place of the optical drive. Even worse the Bootcamp partition was cloned to the 3 TB HD but it won't boot from it. Has anyone had problems using Bootcamp with Windows XP on a 3 TB drive? The shop told me to just reload everything at home but I fear that it might not work.