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TrustedInstaller is a built-in user account in Windows 8, Windows 7, and Windows Vista. This user account “owns” a variety of system files, including some files in your Program Files folder, your Windows folder, and even the Windows.old folder that is created after you upgrade from one version of Windows to another. To rename or delete these files, you’ll have to take ownership of them away from the TrustedInstaller user account.
If you’ve just upgraded to a new version of Windows and are trying to get rid of the Windows.old folder, there’s an easier way to do it – you don’t have to delete the folder by hand.
Who Is TrustedInstaller?
The TrustedInstaller user account is used by the Windows Modules Installer service included with Windows. This service is responsible for installing, modifying, and removing Windows updates and other optional Windows components, so it has the exclusive ability to modify them.
Deleting The Windows.old Folder
If you’re trying to delete the C:\Windows.old folder after upgrading to a new version of Windows and you’re seeing a message saying you need permission from TrustedInstaller, you don’t need to take ownership of the files at all. You just need to use the Disk Cleanup wizard.
To open the Disk Cleanup wizard, press the Windows key and type Disk Cleanup. On Windows 7, click the Disk Cleanup shortcut that appears in the Start menu. On Windows 8, click the Settings category and select the “Free up disk space by deleting unnecessary files” shortcut.
Click the Clean up system files button in the Disk Cleanup window.
If you have a Windows.old folder on your hard drive, you’ll see a “Previous Windows installations” checkbox in the list of system files you can delete. Enable the option and click OK. Windows will delete the Windows.old folder for you – ensure you’ve copied any important files out of it before running Disk Cleanup on it.
Taking Ownership of Files
Warning – the TrustedInstaller user account owns your system files. If TrustedInstaller is preventing you from renaming or deleting a folder, it’s often for a good reason. For example, if you rename the C:\Windows\System32 folder, your operating system will stop functioning and will need to be repaired or reinstalled.
You should only take ownership of system files and rename, delete, or move them if you know what you’re doing. If you do know what you’re doing, follow the instructions below to take ownership of the files.
Locate the folder or file you want to take ownership of, right-click it, and select Properties.
Click the Security tab in the properties window and click the Advanced button near the bottom.
Click the Change link next to TrustedInstaller to change the owner.
Type Administrators into the box and click the Check Names button. Windows will automatically complete the rest of the name. This gives ownership to all administrators on the system. Click the OK button to save this change.
Enable the “Replace owner on subcontainers and objects” setting if you want to apply these changes to all subfolders and files in them. Click the OK button at the bottom of the Advanced Security Settings window.
Click the Edit button in the properties window.
Select the Administrators user and enable the Full Control checkbox to give administrator accounts full permissions to the files.
Click the OK button twice to save your changes. You now have the ability to rename, delete, or move the files as you please.
If you find yourself regularly taking ownership of files, you may want to download a .reg file that will add a “Take Ownership” option to your right-click menu. You’ll be able to take ownership of files and folders with a few quick clicks.
Why did you need to take ownership of a folder away from TrustedInstaller? Leave a comment and share any other tricks you have!