A question about /sfc and System File Checker

Topic

I am running Windows 7 Pro x64, and I recently decided to try out System File Checker, just to ensure that everything in my OS was shipshape. After I entered sfc /scannow in Command Prompt, the verification phase began. After it completed, I received the message: “Windows Resource Protection found corrupt files but was unable to fix some of them. Details are included in the CBS.Log windirLogsCBSCBS.log.”

I checked the log, but it was just programming language to me, and I couldn’t decipher any of it. Does this message mean Windows is permanently corrupted, and I will have to perform a clean install? Or is there a workaround, found in the CBS log, which would permit me, or SFC to fix the trouble? Or could it even be a false positive, in the sense that I’ve installed something that Windows didn’t like (such as a browser add-on or software) and everything is actually fine?

Replies

See if SFC found corrupt files, but can’t fix them – Tech Support Forum or Windows Resource Protection found corrupt files but was unable to fix some of them. help.

Joe

--Joe

Thank you joeperez for those links; they were very helpful! After reading them, this is what I have discovered so far: after /sfc has completed the verification, I had to run another command prompt – posted on Microsoft’s website – that would instruct /sfc to create a more readable .txt file (located in the User directory) of the cbs log. The command entered was findstr /c:”[SR]” %windir%logscbscbs.log >sfcdetails.txt

However, after creating the log, I checked the file and it was absolutely blank. After further research, I found this is due to the nature of the command prompt – the command line that Microsoft posted only instructs /sfc to search for certain errors established by the command parameter. Therefore, if the txt file is blank, it means that /sfc didn’t find any of the errors it was instructed to search for in the cbs log.

I decided to investigate further. I found a very helpful page on Microsoft’s Tech Support website, detailing how to interpret the cbs log file: http://support.microsoft.com/kb/928228 Some of the key phrases to search for are, “Cannot repair member file,” “Repaired file by copying from backup,” and “Repairing corrupted file from store.” Using the trusty find function in Microsoft Word, I checked for each of these phrases, and variations on them, and turned up nothing.

Would this mean that System File Checker created a false positive when it detected so-called “corrupt” files? Actually, this sometimes can happen. When Windows Update installs updates, security patches, and so forth, they can replace certain system files (depending on what was updated) with newer, updated versions. Since System File Checker sometimes only checks for the original version of those files – that is, the files a clean installation of Windows begins with. Since /sfc doesn’t always recognize or monitor the updated versions of these files, it may raise an unnecessary alarm, causing undue panic, or (in my case) confusion. This is not to say that /sfc shouldn’t be trusted, but merely that those who would use it should conduct a deeper study to find if the files found really do need to be replaced or repaired.