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 :)