Re: Permissions issues after installing Windows 10

[Bill Stewart <bstewart@iname.com>]

On Fri, Jun 3, 2022 at 6:23 AM Brent Epp wrote:

I would think so too, but that doesn't appear to be happening. If it
> makes a difference, the SID actually starts with S-1-5-21. I have to
> manually take ownership in order to even access the files at all.
>

Explained another way: According to
https://docs.microsoft.com/en-us/windows/win32/secauthz/well-known-sids -

Constant: SECURITY_NT_NON_UNIQUE
String Value: S-1-5-21
Identifies: SIDS are not unique.

SIDs starting with S-1-5-21 are non-unique, which means basically the SID
is made unique by the addition of a RID (relative identifier).

If the SID starts with S-1-5-21 and ends in 500, it is the local
"Administrator" account of some computer (or domain).

In other words, S-1-5-21 SIDs are computer or domain accounts that the
system couldn't resolve when it enumerated the ACL.

You can see SIDs for local accounts on a machine from PowerShell (all one
line):

Get-WmiObject -Query "SELECT * FROM Win32_UserAccount WHERE
LocalAccount='TRUE'" | Select-Object Name,SID

Note that in the output, these SIDs will start with S-1-5-21 and end with
various RIDs.

Bill