If the drive is working properly, it will spin when you first turn on the computer. If the Floppy is set as then fist boot device, it will try to read from a diskette in the drive. If not diskette present, it will boot for the next available device.
If hyou have a formatted diskette in the floppy but no actual operating system. the boot loader with say:
NTLDR is missing...crunch any key.
Or some similar message. It means then drive is working. A floppy that does not work right may cause the computer to hang on boot.