I've a similar BSOD "unmountable Boot Volume" Stop error 0x000000ED
I've used all the normal methods to repair including the one you've suggested from the media. However I witnessed the same problems. After some period of time you're simply left with a cursor and the blank windows wallpaper. After pressing F8 on boot up
none of the available repair options work.
The machine is brand new along with 30 others, so I've swopped out the harddisk with a known good one and found it boots up fine so there's no BIOS issues to be concerned about. I am also quite confident that the HDD itself is fine and it's purely down to
corrupted W7 files.
As these were purchased through a retailer they are unfortunatley W7 home edition and an upgrade to Pro. Causing me some headache now as to which upgrade key went with which machine.