This article describes two ways to deal with the message in Windows 10 about needing permission from TrustedInstaller to make changes to a file or folder.

How to Fix the TrustedInstaller Error Using Command Prompt

There are two straightforward Command Prompt commands you can use to bypass the TrustedInstaller permissions prompt. Follow these steps to fix the TrustedInstaller “error” by granting your user account permission to modify the file or folder:

1. Open an elevated Command Prompt. The quickest way there is to search for it from the Start menu, right-click the result, and choose Run as administrator.

2. Enter TAKEOWN /F and then type the file or folder name. Here’s an example:

    TAKEOWN /F C:\Windows\System32\fr-FR\fms.dll.mui
   

3. Press Enter to take control of the file. You’ll see a success message if the command executed correctly.

4. Enter the following command (replacing our example file with your own) to immediately give your user account permission to delete or change the file or folder:

    icacls C:\Windows\System32\fr-FR\fms.dll.mui /grant Administrators:F /T
   

Edit the File’s Security Options to Fix the TrustedInstaller Error

If you don’t feel comfortable using Command Prompt to take ownership of the folder or file, there is another way. Here’s how to use File Explorer to edit the security settings for the data, which will let you delete or modify it as needed.

1. Locate the item you need permission to change and then right-click it and choose Properties.

2. Go to Security > Advanced, then select Change next to Owner: TrustedInstaller.

3. Type your username into the text box and then choose Check Names > OK.

4. Check the box next to Replace owner on subcontainers and objects.

5. Select OK at the bottom and then OK on the Properties window you opened in Step 1.

6. Open Properties > Security > Advanced once more. This time, select Add.

7. Choose Select a principal and then type your username in the box.

8. Press Check Names > OK.

9. Check the box next to Full control, then select OK.

10. Check the box next to Replace all child object permission entries with inheritable permission entries from this object.

11. Select OK on the Advanced Security Settings window and then Yes on the confirmation prompts. You should now have full permission to make changes to the file or folder, and you can close any other windows you opened to make these changes.

Why Do I Need Permission From TrustedInstaller?

As the primary user of your home computer, you might be surprised to find you need permission to manage files on your own PC.

All Windows 10 PCs have an in-built Microsoft account known as the TrustedInstaller. This account exists to prevent accidental damage to important system files, so it’s given ownership over many important operating system files. For you to be able to take control of these files, you need to make yourself the owner as described above.