I thought /U was "unconditional", meaning that you cannot later reverse the formatting and recover the previous data. Without /U, FORMAT would save a hidden copy of the FAT (or something like that), IIRC, making it easier to recover from the format. My MS-DOS 5.0 manual says that with the /U, FORMAT "Destroys all existing data on a disk", whatever that means. Bob -----Original Message----- From: Fred Cisin [mailto:cisin@xenosoft.com] Sent: Thursday, August 21, 2003 5:16 PM To: cctalk(a)classiccmp.org Subject: Re: Low Level Format <snip> If /U is active, then it at least "VERIFIES" every cluster. <snip> -- Grumpy Ol' Fred cisin(a)xenosoft.com