If you need to delete or overwrite a system file in Windows 7 or Vista, you’ll quickly notice that you cannot delete system files, even as administrator. This is because Windows system files are owned by the TrustedInstaller service by default, and Windows File Protection will keep them from being overwritten.
Thankfully, there’s a way that you can get around this. You need to take ownership of the files, and then assign yourself rights to delete or modify the file. For this, we’ll use the command line.
Open an administrator command prompt by typing cmd into the start menu search box, and hit the Ctrl+Shift+Enter key combination.
1. Run Regedit
2. Find the registry entry "HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services"
3. Look for the service there and delete it. You can look at the keys to know what files the service was using and delete them as well (if necessary).
4. Restart your system...
