S-1-5-21-3581062555-3082721082-2155200769-1000 is your user account on the
installation that broke. S-1-5-21-3581062555-3082721082-2155200769 is the
identifier of the computer, and 1000 indicates that it was the very first
account created on that computer. Every time you reinstall the computers ID
(called a Security Identifier or SID) changes. All access control is tied to
the SID. Therefore, when you move the drive to a different computer, which
you effectively did by flattening the original installation, it cannot
resovle the actual name associated with that SID because the account no
And, this question actually is answered in the book. :-)
Your question may already be answered in Windows Vista Security:
> Recently my system crashed and 'system restore', repair from Vista DVD and
> sfc /scannow were unable to recover my system except to take me to a
> temporary desktop. This did enable me to copy both of my internal drives to
> my external drive.
> Then, with the guidance of a Microsoft tech, I was able to re-install and
> activate Vista Ultimate. It did change the drive letters but I had named the
> drives "C as of..." & "D as of..." so I knew which had really been the "C:"
> drive. As I did not reformat most of my files remained intact but, of
> course, I did have to re-install all programs.
> When I started getting 'access denied' messages I decided to take ownership
> again of all drives but I discovered that the current owner of my external
> drive had become "S-1-5-21-3581062555-3082721082-2155200769-1000".
> I had taken ownership of all drives and subcontents several months ago. I
> have allowed both Microsoft and Symantec Tech Support to have use of my
> system during help sessions via the internet since then. Other than that
> only my wife has access to my system and she knows nothing about computer
> Does anyone have any idea who this
> S-1-5-21-3581062555-3082721082-2155200769-1000 could be and how my ownership
> status could have been usurped?
> Is there a way to lock my ownership so it cannot be changed without my
> My firewall is Norton Internet Security 2008.
> Thanks for any help with this mystery,
> Norman Castel