Before you do that you might want to check if the IDE cables are seated correctly in the machine with the hard drive as well as the floppy. Sometimes things are that simple. If that does not solve the problem then the above is the way to go, I'd probly replace the floppy to. If your place is anything like mine, the floppy drives we order are POS and they last about a month until they die.
Sounds like you have an old machine and I would venture to guess your harddrive is on its last leg. You should immediately get a backup so that all is not lost. After that depending on the manufacturer of your drive acquire a test software for it.