MAVERICKS CHOICE - Yes, my BIOS fully supports booting from USB. jaclaz - I haven't tried with that method yet. Not sure how it does it's thing but the diskpart method seems works great for Vista. As for my problem I believe it has to do with the boot sector on my usb hard disk drive. I was using a WD Passport 120 Gig USB drive (older model) with 2 partitions. One 10 Gig formatted with FAT32 (Vista Boot Partition) and the second was 110 Gig NTFS Partition. It would build Vista fine, it would not however read the Autounattend.xml. What I mean is that it would build like you were using the original DVD to install Vista. I eventually got tired of trying to figure it out and went with a 4 Gig test flash drive. That worked like a charm, built Vista in roughly 25 to 30 minutes requiring no input from me. YAY.... I'm not really sure why the 120 Gig gave me so much trouble.