The System File Checker (SFC) uses several techniques to detect that one or more of your system files have been either inappropriately replaced or damaged. SFC then tries to repair the problem.
Unfortunately, it can’t repair everything. In your case, that puts you in a hard spot.
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How do Windows files get damaged?
One of the most worrisome reasons is malware, which tries to replace or alter system components with its own malicious code.
Windows keeps a list of all of the system files and their characteristics. Among other things, that’s the “hash” that’s mentioned in the error message you received. If the files don’t match those characteristics, then SFC tries to recover those files from backup copies that Windows maintains elsewhere on your system.
Unfortunately, those backup copies can also become damaged or missing; the reasons why range from malware to an over-aggressive disk cleanup.
Even the database where the information is kept can also become damaged or corrupt. In these cases, SFC simply can’t do its job.
What can I do?
At that point, you have three options:
- Ignore the problem. It’s difficult to make a strong argument for this other than the next two options are painful. When would this be acceptable? Let’s say you’re not actually experiencing a specific problem; you just ran SFC for the fun of it. In that case, you might consider ignoring the problem. But it would make me uncomfortable and a little nervous moving forward. I would certainly run anti-malware tools at this point.
- Perform a Repair install of Windows. This isn’t always an option, but when it is, it can save you some hassle. A Repair install replaces all of the Windows components with the correct ones and keeps that SFC database up-to-date. You may need your original installation media or your copy of Windows for this to be a viable option.
- Backup, reformat, and reinstall Windows and all of your applications and data from scratch. Usually, everybody wants to avoid this option at all costs.
This last step guarantees that you’re back to the point where SFC thinks you should be: a consistent and proper copy of Windows. Nonetheless, it’s a very painful process to get there.