Jethro said:
On Wed, 14 Feb 2007 22:00:18 -0500, "Bill Blanton"
[snip]
I still would like to know exactly what WXP does to a hard drive that
seemingly locks it to a drive. I always assumed that hard drives were
somewhat independent - they were in W98.
XP assigns a signature to every disk it initializes. This sig is written
to the MBR (sector 0)
XP uses the disk signature and volume LBA start sector to "remember"
drive letter assignments. The values are kept in the registry in the
HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices key.
In your opinion, why does WXP do this? To identify the drive to
prevent piracy? To tie a validated XP to one drive?
Just wondering.
I don't think it's anything sinister ;-). Though the method itself is
questionable, it's just a way to identify a drive.
And this is necessary because ???
It provides Windows a mechanism to unambiguously identify physical
disk drives to ensure that it accesses the proper drives.
How this affects cloning is as follows:
With a true clone in which all of the sectors on the clone disk drive
are identical to those on the original disk drive, the disk signatures
of the two disk drives are identical. When Windows is booted up, its
loader checks the disk signatures of all of the connected drives, and
if it see two identical disk signatures, it changes the signature of
the second disk, which would be the clone disk. Once this happens, the
clone disk would not be able to boot up independently of the original
disk, because the MountedDevices fields in the clone's registry
reference the disk signature of the original disk, which would not
exist.
