> when I installed the operating systems the IDE Optical drive was connected
> ...will this new SATA Optical drive necessitate that I reinstall the operating systems
Switching from an IDE to SATA Optical drive should make no difference.
> XP Pro in a dual boot config will I be able to set SATA Mode and Marvell SATA 3
> Operation Mode to AHCI and AHCI not have a conflict with XP Pro?
If you change to AHCI, XP will no longer see your (HDD) drives (I'm pretty sure).
(There may/could be methods to get things to work, after the fact? Seem to recall that I did some odd stuff a long time ago relating to AHCI, but I don't recall specifics? My more recent forays into [even loading SATA/AHCI] drivers for XP were not fruitful.)
You would have to have loaded SATA (AHCI) drivers during your XP install (F6).
Then your drives would work as AHCI in both XP & Win7.
(Do note that some M/B may not need SATA drivers for AHCI - even with XP, IOW, it may work natively. XP SP3 AHCI & SATA Installs With No Extra Drivers Needed)