Don't panic. I didn't lose 15 years of data. I lost an evolutionary dead-end. But that's skipping ahead...
UNBOOTABLE_MOUNT_VOLUME is not a happy BSD (Blue Screen of Death) to see when you restart. My 5-year-old PC running Windows XP Media Edition ("it seemed like a good idea at the time") had gone a long time without BSDs, but apparently the attempt to use Windows Explorer instead of Sonic MyDVD LE to burn DVDs (an honest mistake, for which I forgive Sandra) resulted in sharp, steely sorts of data caltrops being thrown about in precarious places.
The final straw, the BSD from which I could no longer boot, only came when I ran out of space on my portable backup drive. Don't worry -- the stuff I ran out of room on was some movies I don't need. Apparently that BSD kicked some of the caltrops into the boot sector, and Drive C became unbootable, only in ALL CAPS, and with underscores attaching it to other words.
I'll spare you the story of my wrestle with inner demons. I won't bother to regale you with the strings of ear-blistering obscenities, vulgarities, and profanities I concatenated with angry abandon. I'll make only passing mention to my friend Bob Defendi who talked me down from the ledge twice, and my friend Jake Bingham who provided me with hope, if not with the actual tools to solve the problem.
No, the important part of the story is the part where I realized that while I still had all my data (on two different backup drives, as well as on one internal drive), I was going to have to choose whether or not to keep my processes. Installing a new operating system (Win7, about which I've heard wonderful things, and which is, as of this writing, performing flawlessly) necessitated wiping drive C. From there I could easily copy all my documents back, but those directory trees were convoluted.
"Evolutionary dead-end," I said. An example: Before I started creating Schlock Mercenary I used AOL Instant Messenger to chat with friends. At the top of My Documents was a folder labeled "AIM Chats" which hasn't seen new data in over five years. It's at the same level as a directory called "SchlockDocs," which is the parent directory of dozens of nested children. You see, back in 1995 when I first realized I was going to want to save some things pretty much forever, I decided that it made sense to organize them by taxonomy, and the only taxonomies I was familiar with were very general at the top, and increasingly complex at lower and lower layers. So that's how I stored my stuff.
And that's how I stored it for 15 years. When I first started storing stuff that way, the directory trees were on a Mac LCii, or some such. They moved with me, always growing, because if there's one thing you never do to a taxonomy, one thing such trees are never subject to, it is PRUNING. (Note: Feel free to comment with examples of taxonomies that have been pruned. But I bet they got bigger afterwards.)
Windows 7 seemed to suggest, through its "library" interface, that the things I do most should not be leaves on twigs on branches on limbs of a huge tree. They should be front-and-center. In fairness, my old processes included creating shortcuts to the leaves, but this meant my desktop was a mess of shortcuts. Now Win7 was suggesting that there might be a better way. No, it didn't hold my hand through the process of deciding what goes front-and-center. But by looking at how it tried to organize content, I realized that files I am currently working with should go at the top of the library, front-and-center. Once I am done with them, they should be shuffled off onto the D drive (and backed up to G, H, and beyond...) where it's okay to maintain a deeper directory structure.
So that's what I did, and I did it aggressively. My desktop has exactly one icon on it right now. "Recycle Bin." I should point out that I preferred the name "Trash" from the old Mac interface. Files are not "recycled" unless you reuse their contents. Disc sectors are reused, yes, but when I put a redundant copy of Schlock dialog into the Recycle Bin it's not going to show up on your computer as witty repartee. It's TRASH. But I digress. I should have used parentheses. (Like this.)
One icon. My task bar, which auto-hides, is only half full: Windows Explorer, IE, Google Chrome, FileZilla, Windows Fax & Scan, Media Player, and iTunes. Why so spartan? Because the things I do most often are script, blog, trawl, upload, scan, and jam. Oh, and watch Doctor Who.
All my other cruft is buried. I created a directory called, appropriately enough, "cruft" in the My Documents directory, and any time I find myself hitting folders there more than once in a day, I give them a new home on Drive D. Eventually the Cruft folder will go away completely. As I mentioned elsewhere, this is like moving all your stuff into a storage unit, then going into a new, empty house, and only furnishing it from storage as you need things. That cedar chest full of sweaters that don't fit anymore? It never shares four walls and a roof with you again.
This process is painful, but it's the right kind of painful. It's like losing ten pounds and realizing your pants fit correctly again (apropo of nothing, I've done that three times in the last 15 months, each time with a downwardly-trending size of pants. There! I used parentheses this time!)
Soon I'll be replacing this worn-out PC. But migrating my data to a new machine will be fairly painless, because I don't have to carry around a cedar chest full of sweaters that don't fit, and the pants I'm wearing DO fit.