When trying to change system files, this error is commonly experienced: “Access denied: You need permission to perform this action.” System files are protected by TrustedInstaller. Even a user logged in as an Administrator does not have permission to overwrite system files. These steps will allow the user to overcome this error and overwrite system files as needed.
This is some screenshots about the issue(s):
How to fix it:
1. Click the Orb (Start menu), type in cmd, right-click on the cmd.exe and choose Run as administrator.
2. Now, you must take ownership of the file by typing the following command:
takeown /f C:\Windows\System32\wmpeffects.dll and hit Enter (replace C:\Windows\System32\wmpeffects.dll with your file)
If succeed, you will see a message like this:
3. After that, type in the following command. This will give you permission to access the file:
cacls C:\Windows\System32\wmpeffects.dll /G jessica:F (replace Jessica with your username) and hit Enter.
It will ask you whether you sure to do that? Type in Y and hit Enter again.
4. Now, you can easily overwrite system files without any problems.