Jo-Anne wrote:

Thank you again, Paul! Before I attempt anything else, I thought I'd let you
know that my flash drives and my external hard drives still show up properly
and work fine plugged into this port. However, another mouse I tried--a
three-button Logitech mouse--worked only as a generic two-button mouse. For
both the Contour mouse and the Logitech one, when I plug them into the top
USB port and look at Mouse Properties, they show up as what they are; when I
plug them into the bottom USB port, they show up as generic two-button mice.

Jo-Anne

This is purely a guess at this point, but I think your touchpad software
is doing this. Either it's the touchpad software that is supposed to be
there. Or, during Windows Update, some other touchpad software was installed.

Touchpad software is "interested" in HID devices. Your USB storage devices
are not HID, which is why they're not affected. Keyboards and mice are HID
devices. If you had a defective USB keyboard or a defective USB mouse,
it's the touchpad driver I'd be interested in.

Paul