[ALUG] "Hidden partitions"

[Wayne Stallwood]

On Sun, 2007-02-18 at 09:47 +0000, ted.harding at nessie.mcc.ac.uk wrote:
> Hi Folks,
> 
> I understand that many laptops have BIOS-admin and
> diagnostic programs stored in a "hidden partition"
> on the hard drive -- usually accessed by pressing
> a function key during the first stage of booting.
> 
Actually the BIOS admin bit is quite rare these days, I think a few of
the older Compaq's had that, and my very very old 286 Tosh did.  

Another reason for a hidden partition was for the old BIOS based
hibernate to disk facilities which are no longer relevant.

> Any suggestions about
> 
> a) How to find out where this partition is (e.g.
>    starting and ending cylinders) -- indeed to find
>    out whether it is there in the first place?
> 
Often it is at the start of the disk.

> b) How to (e.g.) wipe that other OS off the drive
>    and install Linux without affecting this hidden
>    partition?

When you use fdisk (or similar) if it exists it will appear either as an
unidentified partition or maybe as a small FAT partition. It's not
actually hidden as such it's just in the first case Windows won't assign
a drive letter to a partition it doesn't know how to read and in the
second case they have probably adjusted the Windows installation to not
assign a drive letter to the (otherwise standard) partition.

If you are really nervous you could take a look from the windows (NT,
2000 or XP) installation by punching services.msc into the start menu
run box (or right clicking my computer and selecting "manage") From the
management console you could navigate to disk management and look at the
partition layout of the disk (including any unidentified or unassigned
partitions)

If such a partition exists it will be apparent in fdisk regardless of
it's type.