I am guessing that after the black out - your computer began seeking [on reboot] an operating system - BUT ON THE WRONG HARD DRIVE. There may be a partial installation on your other HD or because the one you have the OS on is corrupt - the pc goes to second HD - finds no OS and repeats. Just disconnect the HD w/o the OS on it. Then Go into your BIOS and insure network boot,etc are off and point it to CDROM as first boot device. When you are asked if you want to repair the first time -decline and continue as if you were doing a fresh install - after a few more screens select install on same partition leaving the same file system intact - sure? 'yes' and Then [I may be skipping some screens] you will be offered opportunity again [totally different option that needs no user input or command prompts, etc.] to repair ... you can try this first if you want. if it fails - next time reinstall same way but go ahead and copy the files over the old ones being sure to leave the file system intact....[you will see this option]. When repaired or reinstalled over old version...You will have to reinstall programs - but alll your data will be there. Then reconnect your second drive.

The problem actually seems to lie within the harddrive.
Windows stop code 0x7B (0x0000007B) is "Inaccessable Boot Device." This usually means windows lost access to the partition/drive the operating system is on.

There is be a series of issues and fixes.
According to what you wrote, the drive is not being seen from windows. This usually means a reformat as the MBR could have been corrupted. Got critical files on there that you want to back up? Well if you have another computer you can use, and a spare CD, I suggest downloading Ubuntu and burning that onto a CD. No I am not implying installing Linux, you can use it "Live" meaning it will start up without installing anything to the hard-drives. You can boot into the Live Linux, and under places you'll find all your partitions on any file system they are (Linux will see and read NTFS partitions). Just open up the hard-drive the OS (Windows) is on, and go to another drive and drag and drop!

Now, what I just said above has a possibility not being a viable rescue plan for you. The only hold back is checking BIOS and seeing if the drive is being recognized. If BIOS does not see your drive, we're pretty much at SOL levels. If the BIOS cannot see the drive, you're going to have to forget about the drive. I sure hope that is not the case!

I hope the first solution I gave you works for the problem :)