My system: AMD Athlon X2 6000+ Asus Crosshair (nForce 590 chipset) motherboard (2) WD Raptor 75GB HDD in RAID 0 running off the nVidia RAID controller Seagate 500GB SATA HDD (was D:/ for My Documents on my XP Pro setup) 8GB of Kingston HyperX RAM (in XP Pro 32 bit it naturally displayed only 3-ish GB but in BIOS all 8 reported) Asus Radeon HD4870 video card Creative X-Fi Fatality Xtreme Gamer Pro edition (PCI) (2) DVD drives Floppy drive Attempt 1: I used my Partition Commander v8 program (by Vconn) to delete and reformat the RAID array drive as NTFS. During boot the array POSTed as “healthy”. I booted off the Vista CD and the installer recognized the RAID array as a single drive and associated it with C:/ The Seagate drive was D:/ Installation proceeded smoothly, no RAID drivers necessary. I installed all my motherboard and peripheral drivers just fine using my 2nd optical drive. There were a total of 3 reboots during driver installation. When I finally removed the Vista install media and tried to reboot I got a “non system disk” error. I could only boot up if the CD were in the first optical drive. I triple checked that the BIOS had my RAID array HDD as the first HDD listed and that the boot order was HDD first, CD second yet I could not boot my system sans Vista installation media. Attempt 2: I used Partition Commander to delete the partition on the RAID array disc. I went into the RAID software at boot and rebuilt the RAID array from scratch. I installed the 3 RAID drivers (the newest drivers were diligently downloaded to my thumb drive) during Vista installation when I was prompted. Vista detected the array just fine and reported it as unpartitioned space as it should. I let Vista format the C:/ this time and installation proceeded smoothly. Once the basic install of Vista had completed I removed the installation media before I installed any drivers and did a reboot. I was again presented with a “non system disk” error. If I reinserted the Vista CD I could boot. Attempt 3-5: I tried various combinations of formatting and BIOS structuring. All with the same results. I could get Vista installed to the RAID array but I could not get it to boot off the RAID array. One irritating fact was that with each successive reinstallation attempt I would add another “dummy” Vista OS listed at boot. Considering I was wiping the “C:/” clean between each install attempt I don't know where this was being tracked. XP never had such problems. Current condition: I have disconnected both my Raptors and have installed Vista to my Seagate drive. It works fine but I have this RAID 0 array that has worked in XP Pro for 2 years sitting un-powered in my case because Vista refuses to boot from it. Any ideas?