What is the most likely problem if the drive light on a newly installed floppy drive stays lit after booting?

If the drive light on a newly installed floppy drive stays lit after booting, one of the most likely problems is that the ribbon cable is connected backwards. Floppy drives are designed to receive signals from the motherboard via the ribbon cable, which has a specific orientation that must be maintained for proper functionality. If the cable is reversed, it can cause the drive to continually engage its light, as the data signals are not being processed correctly. This continuous lighting indicates an error in communication between the drive and the computer, often caused by improper connections.

The other options present different issues. For example, if the drive is not receiving power, you would not expect the light to turn on at all. A write-protected floppy disk may prevent writing to it, but it wouldn't cause the drive light to stay on continuously. Lastly, if the floppy drive were incompatible with the system, it might not function or be recognized at all, rather than just keeping the light on. Thus, the behavior of the drive light staying lit suggests an issue specifically related to the orientation of the ribbon cable.