Hey guys, I thought I'd share some light on this topic (or at least try if it hasn't already been done). XP Professional upgrade DOES WORK, when upgrading from XP Home on a Mac. I did this on my MACBOOK PRO just a few moments ago. I used the FAT32 partition so that I could see the files in OS X. Here are this steps: 1) Do exactly what the instructions state for the Boot Camp/Windows install 2) Install the FULL Version of XP HOME 3) Once you have XP HOME loaded and running, insert the MAC OSX disc 1 ( this will install the MAC drivers) 4) When this is complete and your computer restarts, get back into Windows and check to see if MAC buttons/functions are working. If so, go ahead and insert the XP PRO disc, but DO NOT INSTALL/UPGRADE FROM WITHIN WINDOWS! 5) Restart the computer with the XP PRO UPGRADE disc still in drive and press the key to boot from the XP Pro CD. 6) Choose the C: drive (the same drive that XP HOME is installed). XP PRO Upgrade will need to see where the ORIGINAL XP HOME is located. 7) Choose the FAT32 or the NTSF partition ( keep the same option as you did during the initial XP Home install) 8) You can do quick format since XP HOME was already here. 9) just let you computer run. Everything else is pretty self explanatory! Let me know how it goes! I did it on this machine to see if it would work and it does! However I'm sending this one back because of a DEAD pixel, new one is already on its way, and I'm gonna do the same process.