Have you ever tried to remove or overwrite a System File in Windows 7 or Vista Windows System Files but are unable to even though you are logged on as administrator? The reason for this is that by default TrustedInstaller service owns Windows System Files and Windows Protection prevents System Files being manipulated by the user. In order to manage the particular System File you will need to obtain ownership of it and assign yourself the ability to modify or delete the files.
Click Start and type CMD in the search bar. Right click CMD and select Run as administrator.
The Command Prompt opens. Take ownership of the System File by typing the following command:
takeown /f C:\Windows\System32\[System Folder]\[System file]
Note: The example above uses system folder: en-US and system file – audiodg.exe.mui .
Assign yourself full control rights to the file by typing the following command:
cacls /fC:\Windows\System32\[System folder]\[System file] /G [Username]:F
Note: The example above uses system folder – en-US, system file – audiodg.exe.mui, and username – Denise
Now you should be able to overwrite or delete the file. If you are unsuccessful, attempt to boot the computer into safe mode and try again.