How to manually fix a corrupted system file

I’ve already written a PowerShell Script to perform this task. Search for it within this blog. Meanwhile, here are some lines to demonstrate the manual process of getting this done.

a. Seize ownership of file
takeown /f %WINDIR%\system32\{filename}

b. Grant Administrators access
icacls %WINDIR%\system32\{filename} /GRANT ADMINISTRATORS:F

c. Replace corrupted file with a known good copy
COPY SOURCE_FILE %WINDIR%\system32\{filename}