Try doing this.
1. Open a elevated command prompt.
2. In the elevated command prompt, type takeown /f (full path of file) and press Enter.
NOTE: Substitute (full path of file) with your file's full path. For example,takeown /f C:\Windows\System32\en-US\winload.exe.mui
3. A message will be displayed that this completed successfully. This will give you ownership of the file.
4. In the same elevated command prompt, type icacls (full path of file) /grant (user name):F and press Enter.
NOTE: Substitute (full path of file) with the full path of the file and (user name) with your user name. For example, icacls C:\Windows\System32\en-US\winload.exe.mui /grant Brink:F
5. A message will be displayed that this completed successfully.
NOTE...