Command Prompt: Add Local User Account To Local Group

Purpose: Add a local user account to a local group on a Windows computer.

Run the following NET USER command in a Command Prompt window using a local administrator account:

NET LOCALGROUP <local-group> <local-user> /ADD

Notes:
<local-group> : Local group to add local user account to
<local-user> : Local user account to be added to local group

Reference:
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/cc725622(v=ws.11)

Related:
Command Prompt: Add New Local User Account – CodeCentral.com
PowerShell: Add User Account To Local Group – CodeCentral.com
PowerShell: Delete/Remove A Local User Account – CodeCentral.com