I ran into the same problem several year ago with a used Rebel 300D when I was was running Win7. I suspect they're kept busy enough keeping all the newer camera equipment compatible. The short answer is that windows, and probably Canon for that matter, have no logical reason for continuously upgrading their software so that a nearly 20 year old camera is recognized on a more widely used modern operating system.
I'm guessing that Win10 only sees the camera's CF card as an external storage device but not the camera itself when connected to your PC with a USB cable.
