I'm setting up a new PC and am planning to dual-boot XP Home (32 bit) and Vista Home Premium (64 bit). It will be a clean install of each OS on a newly formatted hard drive. I have two SATA hard drives (a 74 gb WD Raptor and soon-to-have a 640 gb WD Caviar Blue). I'm looking for some advice about installation issues, so any opinions and links to threads or other resources are appreciated. Which OS should I install first, and/or does it make a difference? Should I install both OS's on the faster Raptor in separate partitions, or is it better to install each OS on a separate drive (from what I have read, the WD 640 is one of the fastest 7200 RPM drives available). If I install Vista first and decide later to dual-boot XP for legacy apps/peripherals, can it easily be done? I.e., can I create new partitions after installation with Vista, or do I have to reformat like with XP? Whether or not both OS's are on the same disk, will I still be able to install programs from both OS's to my larger disk when the Raptor fills up? Will I be able to access data/media files from either OS? Thanks!!