Trustedinstaller Permissions [2025]

icacls "C:\Windows\System32\example.dll" /setowner "NT SERVICE\TrustedInstaller"

| Account | Default access to protected system files | |--------|-------------------------------------------| | TrustedInstaller | Full control (owner) | | SYSTEM | Read & execute | | Administrators | Read & execute (can’t modify by default) | | Users | Read & execute | | All other accounts | None / limited |

icacls "C:\path\to\file" /setowner "NT SERVICE\TrustedInstaller" trustedinstaller permissions

# Take ownership (admin CMD) takeown /f "C:\Windows\System32\example.dll"

Before modifying any TrustedInstaller-protected file, run sfc /scannow and DISM /Online /Cleanup-Image /RestoreHealth – often they repair the file without you needing to manually replace it. icacls "C:\Windows\System32\example

October 26, 2023 Subject: Security Architecture and Operational Behavior of the TrustedInstaller Identity

Or via → type NT SERVICE\TrustedInstaller (on domain-joined PCs, switch to local computer context). TrustedInstaller is the security principal used by the

This report provides a comprehensive technical analysis of the "TrustedInstaller" user identity within the Microsoft Windows Operating System. TrustedInstaller is the security principal used by the Windows Modules Installer service to manage system updates and component maintenance. It holds supreme authority over critical system files, possessing permissions superior even to the local Administrator account by default. Understanding TrustedInstaller permissions is essential for system administrators, security professionals, and forensic analysts to maintain system integrity without inadvertently causing system instability.