Well, it does respond to the F2/F3 commands in MHDD, but here's the really funny part - chalk it up to age I suppose (I'm approaching 50 now and been working with computers pretty much daily since the mid-1970s...):
So I read this thread, then I read it again, scan it again, keep coming back to it feeling like there's just this one little tidbit of info that I'm missing, etc - the one piece of the puzzle that keeps eluding me.
I decide to plug the drive into test desktop I have (with Windows 7 Pro on it) and just let it sit there for a while. For whatever reason, Windows 7 actually detected the drive (it was seen by the BIOS) - the test machine is the Dell Dimension 4600 I mentioned previously, and an update on that as well: it's got an ICH5 chipset/controller, not ICH6, maybe that makes some of the difference, I don't know.
Anyway, Windows 7 detects the drive, it shows up in Device Manager but Disk Management can't do anything with it nor can diskpart (both give the expected I/O errors but the drive is
visible to both). I decide to see what A-FF Repair Station tells me with their unlocking diagnostic - their website says they can unlock
any WD drive so, I grab the tool, install it then run it and when it starts looking for drives, the WD disappears from Device Manager completely, and after about a minute or so the unlocking tool says yep, it can unlock the drive. I cancel the Repair Station diagnostic and about 2 minutes later Windows still hasn't seen the drive again so I do a refresh in Device Manager (right click the computer name at the top and "Scan for hardware changes" - the drive is detected again by Windows at that point and so I leave the machine to sit for a while.
Amazingly, after about 3 more minutes, I see a new drive letter in Explorer and the volume label is SYSTEM RESERVED which is obviously the small 100MB partition at the beginning of this WD drive, and about 2 minutes later I see "Acer" appear as a second volume label and bells start going off in my head... DING... DING... DING...

I click the Acer volume and it loads in Explorer but it does so excruciatingly slowly. Now, when I checked the S.M.A.R.T. status of this drive originally it was completely clean - green all the way, not one bad sector was listed but, that could be because of some interference with the password protection, I don't know. I couldn't actually do any kind of surface scan of course but, the drive seemed to be reporting it was in good shape at that time.
That's when the magic moment happens: I remember that back in a post in this thread someone listed a few master passwords, and one of them said something about "acer" so... I go back to the beginning of the thread and scan the first few pages, find that post with the master passwords, know that I've already tried the WDC-repeat ones and had no luck, then I see it: h20insyde
It can't be that easy, can it? Well, let's find out. Reboot the PC, load MHDD off my USB stick, Shift+F3 to detect the drive, UNLOCK, 1 for master password, then h2oinsyde and... I'll be damned.
Done.In bright green letters, and boy did I smile big and wide. Did DISPWD and removed it permanently and now the drive is unlocked.

So I figure let's run a proper scan for any potential defects at that point and see what happens. I start the surface scan with F4 and the defaults and it's zipping along at 73MB/s average read speed until about 2.1% in and wham... bad sector... and another... and another... and another, etc... I wasn't doing the repair/erase waits at that point, just the scan, so I stop it and restart with the repair/erase waits option, it gets to the same point and starts showing W... W... WW... WW... oops... x... another WW... x... so now I'm kinda disappointed.
I stop the scan again, hit F8 for S.M.A.R.T. status and now suddenly there's errors showing up, a lot of them. Reallocated sector count is 113 where it listed nothing before, not a single one. Lots of errors now and I don't know if they're actually there or the firmware is hosed so severely this drive isn't going to be of much use, I really don't know.
So that's where I stand now (as of Thursday evening) but I did a longer scan this morning and now the reallocated sector count is 384, I figure the drive is toast, or something is just seriously wrong. When I attach it to the machine directly with the SATA controller, MHDD can see it, the BIOS/controller sees it, Windows sees it and can access it (but again, excruciatingly slow access speed, like a full minute just to refresh a directory listing), and I'm not sure where to go or how to proceed.
If the firmware is corrupt I haven't got a clue how to fix that if it's even possible. The drive is silent, it's not making any noise or clicking sounds whatsoever so, I don't *think* it's damaged, there's no physical damage to the outside of any kind, not a mark on it, but apparently it was inside an Acer or Gateway laptop previously hence the h2oinsyde master password actually working.
If anyone has any suggestions I'm open to 'em. If it's truly toasted and useless, at least I learned a few new tricks in this process I suppose, but I sure would love to get this drive working 100% if it's mechanically and electronically sound. I don't know if it's actually damaged to the degree the scans keep telling me, so if there's something better than MHDD for testing or repair, I'd love to know how to get it done.
Thanks for reading...
ps
I'll do an HDAT2 scan here after I finish this post and reboot, will report back the results.