I went onto Dell's site, and couldn't seem to find any support info unless I logged in. I logged in, and it only knows about the machine I bought a few weeks ago, and has no clue about my old laptop. So I *could not get any suppor for the laptop*. (I probably could if I dug up some very long numbers. But I just want to download some files.)
Installed the removable CD drive, dug up my original drivers CD, put that in, looked through the list. Found nothing for configuring the monitor, so reinstalled the entire video driver setup. Reboot, and it has in fact fixed the monitor setting. But this also blows away a bunch of things: updated drivers I'd installed before, it forgets that I am set to 'Large Fonts' (everything is scaled up to 125%)--which means I have to reboot *again*--and also the settings for my task bar (auto hide, small icons in start menu).