In Windows , each domain and local user, a group or other security objects are assigned a unique identifier — Security Identifier or SID. It is an SID, but not the user name, that is used to control access to different resources: network shares, registry keys, file system objects, etc. We now learn to get SID by username and the reverse procedure – how to determine Windows username by SID.

To translate username to SID you can use an excellent tool from Sysinternals kit — PsGetSid. But you will have to download it and install on each computer manually.

It’s much easier to use the command prompt or Powershell script.

How to Get SID of a Local User

To get the SID of the local account on a given computer, you may use wmic to get access to the WMI storage. For a local user test_user, the command will look like this:

wmic useraccount where name='test_user' get sid

wmic useraccount where name='test_user' get sid

In this example, the user SID is S-1-5-21-1175659216-1321616944-201305354-1005

If you need to get the SID of the current user, run the following command:

wmic useraccount where name='%username%' get sid

In PowerShell, the script returning the same result can be written using two classes SecurityIdentifier and NTAccount.

$objUser = New-Object System.Security.Principal.NTAccount("LOCAL_USER_NAME")
$strSID = $objUser.Translate([System.Security.Principal.SecurityIdentifier])

How to Convert Domain UserName to SID

The following command can be used to get an SID of the current domain account:

whoami /user

whoami /user

To get an SID of a domain user, you can use Get-ADUser cmdlet being a part of Active Directory Module for Windows PowerShell.

Get-ADUser -Identity 'jabrams' | select SID

Get-ADUser select SID

If you don’t have the AD Module for PowerShell, you can request data from the domain using PowerShell as follows:

$objUser = New-Object System.Security.Principal.NTAccount("","jabrams")
$strSID = $objUser.Translate([System.Security.Principal.SecurityIdentifier])


The same command in one line:

(new-object security.principal.ntaccount “jabrams").translate([security.principal.securityidentifier])

How to Convert a SID to User Name

To get the name of the user account by the SID (a reverse procedure), you can use one of the following commands:

wmic useraccount where sid='S-1-3-12-12451234567-1234567890-1234567-1434' get name

In PowerShell using AD Module for PowerShell:

Get-ADUser -Identity S-1-3-12-12451234567-1234567890-1234567-1434

Or like this:

$objSID = New-Object System.Security.Principal.SecurityIdentifier ("S S-1-3-12-12451234567-1234567890-1234567-1434")
$objUser = $objSID.Translate( [System.Security.Principal.NTAccount])

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