The executable file trustedinstaller.exe from Microsoft is the process called Windows Modules Installer, which is a core component of software Microsoft Windows Operating System. This process is a Windows service that launches during startup, and allows the user to download, modify, remove or disable fixes, patches and upgrades from the Windows Update and its optional components. Errors related to this file will result to failure in installing or uninstalling Windows Updates. It is located in the folder C:\Windows with a file size of 194.0 Kb.