You didn't specify whether you see the floppy disk as part of the virtual hardware associated with the VM, or if it shows up within the guest OS. zXi_Gamer and vfk's recommendations address the issue if it's showing up with the rest of the virtual hardware. If you don't have a floppy drive as part of your VM configuration but it still shows up in your guest OS, you may have to go into the VM's BIOS to disable the floppy disk controller.