Windows Modules Installer
TrustedInstaller.exe is safe and critical. It's the Windows Modules Installer that installs, modifies, and removes Windows updates and system components. High CPU during updates is normal.
TrustedInstaller.exe is the Windows Modules Installer service, responsible for installing Windows updates and managing system files. It has the highest privileges in Windows - even administrators need TrustedInstaller permission to modify certain system files.
TrustedInstaller has the highest privilege level in Windows - even higher than Administrator accounts. It owns critical Windows system files to prevent accidental or malicious modification. Even if you're an administrator, you need to take ownership of files from TrustedInstaller to modify them.
Important: If TrustedInstaller is using high CPU/disk for extended periods (30+ minutes), Windows is likely installing updates. Do not force-stop it, as this can corrupt Windows installation. Let it complete naturally.
Yes, TrustedInstaller.exe is critical and safe - it's a fundamental Windows component responsible for update installation and system file protection.
C:\Windows\servicing\TrustedInstaller.exeWarning: TrustedInstaller.exe in any other location is malware. It should ONLY run from C:\Windows\servicing\. If it runs constantly without Windows Update being active, or if you see multiple instances, scan immediately with antivirus.
TrustedInstaller is notorious for causing high disk and CPU usage during Windows updates. This is completely normal but can slow down your computer.
Pro Tip: If TrustedInstaller has been running for 3+ hours without progress, check Windows Update in Settings. If it's stuck, restart your computer and let Windows try again. Use Windows Update Troubleshooter if problems persist.
You can temporarily stop it via Services.msc (Stop "Windows Modules Installer" service), but it will restart next time Windows needs to install updates. Stopping it won't speed up your computer - it only runs during updates. If it's running constantly, you likely have stuck Windows updates that need to be resolved.
TrustedInstaller owns critical Windows system files to prevent accidental deletion or modification that could break Windows. To take ownership: Right-click file → Properties → Security → Advanced → Change owner → Enter your username → Apply. Then grant yourself Full Control permissions. WARNING: Only do this if you know what you're doing - deleting system files can make Windows unbootable.
The legitimate TrustedInstaller.exe from Microsoft is NOT a virus. However, malware sometimes disguises itself with this name. Verify it's located in C:\Windows\servicing\TrustedInstaller.exe, has Microsoft's digital signature, and only runs during Windows updates. If it's elsewhere or runs constantly, it's malware.
1) Let Windows Update finish if updates are installing. 2) Run Windows Update Troubleshooter. 3) Clear update cache: Stop "Windows Update" service, delete C:\Windows\SoftwareDistribution contents, restart service. 4) Run 'DISM /Online /Cleanup-Image /RestoreHealth' and 'sfc /scannow'. 5) Check disk for errors with 'chkdsk /f /r'. 6) As last resort, manually reset Windows Update components.
This process typically runs during Windows Update operations and can cause high disk and CPU usage. This is completely normal during update installation.