Well, I thought it was the Samsung drive, but it's a Seagate (not that it really matters.) I copied NTDETECT.COM to the root directory, and now it fails with some missing DLL. My data files seem to be okay. I'm going to leave it alone and powered-off and wait until my new laptop gets here, then copy the data files to it from the old HDD.
Did I mention the "new" (recertified) laptop?
Thinkpad T410 with a 320GB hdd, DVD-RW optical drive, 4GB of ram, and Win7 Pro (I think that's all the major specs) for $325. Free shipping, and a free 1 year extended warranty. I did have to pay sales tax.
I don't know if there's an empty RAM slot, HDMI port, Firewire, etc. The spec sheets for used machines are a bit lacking in details.
I may put Linux on the old laptop using that spare Samsung drive, just for S&G's.