Thanks, all. I'm familiar with the kind of "lost" taskbar y'all are talking about -- my then 6-yr old taught me how to disappear and retrieve it when we first got Win95!
It's definitely at the bottom, but not even a little gray line shows. If I fish around down there, I can sometimes click on the Start button; it seems to be about an inch below the edge of the monitor. I've been using the Windows button on my keyboard, and keyboard shortcuts to work with my open programs. I'm a mouser, so it's a pain in the neck!
It's as if my screen is 12" deep, but the monitor only shows the top 10"...
I think it has something to do with screen geometry, but like I said, the buttons don't work to change that. I'm tempted to borrow a monitor (wot a hassle!) and see if that helps...