Windows unable to complete format.

How did you format the computer, inside windows or outside?
Try this change the boot sequence from the BIOS instead of booting first to HD make your optical drive as first boot. After changing the boos sequence insert the windows vista disk to the drive then restart the computer. When it boots it will ask you to press any key to boot to CD/DVD. Keep tapping on space bar. If you notice it will say windows copying files. When copying files completed we isolated the problem dvd rom is fine and the vista installer is fine as well.
If the problem only started in or during attempting to format you HDD might causes the problem.