Is my HDD actually empty?

[Pup]

I've got a couple of old SATA I drives knocking about which I was thinking of selling. When I took them out of my old PC I did a full format on them, but recently I thought I best run Eraser (or something similar) to make sure there is no recoverable data on them.

However when I connected them up to my vista laptop (via USB using a WD elements cage), and get the drive properties, both drives show about 90mb being used, even though windows explorer shows no files on them. Essentially the disk space piechart shows 100% free, but the used space shows roughly 90mb.

I know i've seen empty drives use some space up, but isn't 90mb a bit much? It made me curious as to what is contained within it.

I ran a chkdsk on one of the drives which gave :



showing the 91mb split up into a 65mb log file and 21mb in 8 files (!?) and some used by the system.

Should I be concerned about what this space is being used for, and is there anyway to clean this out?

[peterb]

Running a format will not ensure that there is no recoverable data on them. All that does is remove the file system and/or the partition tables (depending on how you formatted it) The data remains there.

Connecting a drive to a windows system will write some data to the disk anyway.

A Google search will find a number of true disk erasers, or you could use a linux live CD and some of the tools found on that.

[jimborae]

I find dBan is very good for doing total hard drive wiping. It's free, simple and you can choose which algorithm to use.

[Pup]

Don't mean to sound rude or anything, but I'm not after software to wipe the empty space of my hdd, in my post I did say I was already planning to use Eraser, and i've read the other thread on here where several disk wiping utilities are mentioned. Surely any disk wiping software such as eraser or dban is only going to wipe over the part of the drive that I can see via windows explorer ? So yes, I am going to run an eraser like tool, but that isnt my problem

What I was hoping someone would know, is what is that 91mb on the drive listed actually taken up by? Is it normal for a 'blank' drive to have a hidden 65Mb log file, and what are the 8 files @ 21mb that chkdsk can see, but I can't?

My concern is that I can't access that (91mb) part of the drive, and don't really want to hand the drive over to someone without having an idea of whats on there.

[Templar87]

I'm not entirely sure on this one but, as you note, the space seems to be taken up by some kind of Windows log file.

Using a tool from outside Windows such as a Linux live cd (as peterb suggests) or Eraser, if you can boot straight to it, should assure you that everything is removed (including anything Windows has created).

[peterb]

Windows does write hidden files to disk, although I'm not aware of any that it writes outside the normal NTFS filessystem (apart from the MBR and partition tables in the first sector, and the swapfile) It is possible for a disk to have 'hidden' areas, such as the host protected area (HPA) but that is a low level function accessed via the ATA command set, and if that was enabled you wouldn't see it without some very specialised software.

To be certain or to find out what it is, you would need a disk editor like Nortom disk ed (if you can find it) or winhex. A linux live CD would give you a method of acessing it natively, (not particularly easily) or you could use a specific tool like Linux Disk editor (lde) which would make it easier.

Sorry can't be more help (but it something I might look at when I have time - but it won't be soon!)