enabled. when disabled in BIOS it does not hang. why?

Floppy drive is needing replaced?The system is looking and waiting for a boot disk?Try altering the boot sequence in BIOS so the computer leaves the floppy till after the HD in the boot sequence.

Check that the floppy cable is not on the wrong way (Green LED light on the front of floppy drive on all the time) failing that try a different floppy drive/cable.Cheers!

Most likely a bad floppy drive.

If the floppy is working in bios but freezes in windows, it could indicate a faulty driver or a system resource conflict depending on how old your system is. Try re-installing the floppy device drivers, if you've installed new hardware resently try uninstalling then check to see if that resolves the issue. If that doesn't work you may need a new floppy drive which are very in-expensive these days.

It's telling you to stop using floppy drives. Seriously, get rid of the drive - you could always boot from a cd if you need to. Use memory sticks or cd's (very inexpensive now) for a much more reliable way of transporting data.