Ok, when I was using XP, once in a while I heard a noise like my hard drive was shutting off (very rarely). THis time it happened and my computer froze so I reset and I got an unmountable boot volume ...
Update: Before you try all of this, you may want to try using WinToFlash, a utility designed to create a bootable Windows flash drive for Windows XP/Vista/7/Server. If this works for you, you can skip ...