sorry i dont know if i m allowed to comment or not,
i think that the os part of the hard disk got corrupted becoz of the BSOD, just for a check if it isn't related to hard disk,
insert a HBCD, boot into live XP and see if you can access your OS partition and its Files
You can try this:
Insert Windows 7 DVD, boot from disk, click repair computer, after awhile use Command prompt and run this command:
Chkdsk /r c: (or d: if you have a recovery partition).
Once done run this command:
That should fix.
Chkdsk /r will take you awhile to complete. It might "hang" on step 4 for over an hour. If that is the case, close command prompt and run again the same command.
I had to do it twice to bypass the 50% mark in my case on step 4.
after the second time, I closed command prompt, ran the fixboot command and then was able to boot into windows to be able to schedule a chkdsk /r upon boot and not using the recovery console from windows 7 disk.
Once looged into windows, ensure you are on an administrator account and Run Command Prompt: Type the following commands in the order described (whats in bold):
fsutil dirty query c: (C drive being the one you have the OS installed)
Once done: chkdsk c: /r
It will ask you to schedule on boot, do it and go make a coffee, eat and come back after 2 hours (on my 640gb hard disk is what it took).
That's how I resolved both the error you have had as well as the blew screen on boot which caused unmountable boot volume error.