Your a drive is your floppy Im just assuming, and if there is no disk in the drive, it will often show up as full, if there is a disk in the drive and it is not full do a chkdsk on it to make sure the drive has no bad sectors,
as far as your d im just guessing here but its probly a cd-dvd or cdr/cdrw drive, and all cd's no matter how much space they have on them as oposed to how much has been used will show up as full both on the pie graph and on the command line, check it out for yourself insert any cd and go into you command line , then into your cd drive and type dir , no matter how much space is being used it will always show space available as 0.
