Even FORMAT can render disks with unrecoverable data. Just invoke the full format and not the QUICK format...
You may be working too hard.
Still not good enough? Get a bulk eraser.
hi, I just downloaded killdisk and can't get it to work-- swapped drivers, disks, etc., no go. anybody know of a similar free utility for erasing floppy drives before trashing/ recycling? and any ideas on how to recycle? thanks - fj