I have experienced a
BSoD error that came up as UNMOUNTABLE_BOOT_VOLUME, what i did is as follows: changed the boot priority, so that the first boot device was the hard drive, changed the position of the hard drive to primary master, if you have an old IDE hard drive, change the position of this (if necessary) to the master position on the ribbon (i used to go into my pc all the time and change everything around, so i had this problem regularly, i had 2 hard drives, and only one of them had a bootable OS)... if this doesn't help, then you dont have a bootable operating environment on the hard drive you are trying to boot from, or it's rather badly damaged, hope this goes some way to helping, and if you could possibly give an update stating any developments or whether this helps at all, it would be appreciated, anyways, buhbye for now
Update: kinda took too long, and wolfeymole beat me to it lmao :O