HI all, so I have the sweetest-running PC ever, my Shuttle. Since I posted my initial install questions six months or so ago about my new Shuttle SP35P2, I've never had a crash, bluescreen, or hang. Honestly, never ever. I'm running Windows XP, 8GB (yes I know, 4GB wasted) RAM, 1TB SATA, and using Photoshop CS4, Premiere Elements, Lightroom 2/3 Beta, various Canon DSLR/video software stuff, full Nero stuff for CD/DVD work and video re-coding, and so on. So not just web-browsing here. Unfortunately when I installed XP I wasn't aware of the future consequences of choosing IDE vs. AHCI, and installed XP with the SATA set to ATAPI/IDE. I'm aware that the performance benefit for my case should be close to zero and so normally changing it wouldn't make sense. However, I now have to run another OS where the SATA AHCI setting is mandatory, and since it's a global BIOS setting, I'm pondering over what to do: 1) Change the SATA BIOS setting, and break the current XP install. It seems a re-install of XP is recommended at least, would a full re-install be required, or can a repair do? 2) Yank the 1TB SATA and plug it into an external USB/Firewire enclosure, install a new SATA (SSD? ;-) internally for my new OS, change the SATA BIOS setting (to live with my current perfect XP system booting off the external USB), and install the new OS on the internal drive? I did leave plenty of partition space on the existing drive to play around, so I can clone the existing system partition etc. before doing anything irreversible. But at the end of the day, what I really would like to have, is my existing XP installation bootable, as well as the new OS installed as a second boot option. Any thoughts would be welcome, particularly about the "Existing XP install on SATA/IDE, moving to SATA/AHCI" headache, and exactly what that would mean. Thanks in advance!!!