It sounds like the floppy drive controller got turned on in BIOS setup.
Reboot and press F2 before Windows starts to load to open Setup. Look for the Diskette Drive option using the arrow keys to navigate, and set that to Disabled, assuming you don't actually have an internal floppy drive in this system.
Be sure to save the change before exiting setup. That should stop the error message when booting.
BTW: Are the computer's date and clock correct? If the motherboard battery is dead/dying, things like the date/time are wrong and the floppy drive controller can get turned on. In that case you may need to replace the battery (CR2032 lithium ion battery, ~$2 at discount stores). See the owner's manual for instructions to remove/replace the battery