Well formating a hard drive will not get rid of the A: Drive since its the drive that is needed to use the boot disk to get windows..
I would say it probably got knocked and now there is a loose connection and is making the floppy go on the blink.. also you could try and have a browse around the BIOS and see if you have the floppy listed as connected anywhere..
It could have been accidentaly disabled..
Hope some of that helps you out

Albert.
