SFC /Scannow Failures

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PC. Win 10 slow as molasses etc.  SFC /scannow does NOT fix some corrupted files.  DISM attempts using different souces fail.  Help!!

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Have you downloaded anything recently that would coincide with this deterioration in performance ?

Can you boot into Safe Mode with Networking then download and run a scan with the free ESET Online Scanner just to check if you are infected.

https://www.eset.com/uk/home/online-scanner/

Can you then open a Command Prompt (Admin) and perform a chkdsk /r

When that has completed, open Event Viewer and when it has read the data, expand Windows Logs and click on Application/Action/Find and type chkdsk or wininit into the Find box and press enter.

Cancel the Find box and use the scrollable window below to view the chkdsk log.

Primarily you are looking to see if it reports any KBs in bad sectors.

If that comes back clean, can you perform another sfc /scannow to see if it still reports files it is unable to fix.

If it does, then download and run SFCFix.exe and post its log.

https://www.majorgeeks.com/files/details/sfcfix.html

You may need to perform a repair install which doesn't affect personal stuff or installed programs.

For that, you will need Win 10 install media which you can create after reading the instructions at https://www.microsoft.com/en-gb/software-download/windows10

When you've done that, with the machine switched on and the media inserted, open Windows/File Explorer - This PC and double click on its drive.

This will start the process when using a DVD but will open to its files when using an USB where you would then double click on setup Application.

This takes 3½ - 4hrs on mine.

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Prior to executing your  instructions, I ran the Pre-Open Scan and corrected the errors reported.  This resulted in improved performance! Earlier, I had run a malware scan which showed no threats.  Then I rean chkdsk /r as instructed. EventViewr showd no errors! This showed marked performance boost!  Still, SFC /scannow showed unfixed files after 3 runs.  Downloaded and ran SFCfix.  It crashed near the end which was reported to developer.  RE: media creation tool.  Downloaded to USB.  As I write, I have not run the repair.   I will post further when I have completed repair.  Many, many thanx for your help.

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Before you perform the repair install (if you haven't already), can you run another sfc /scannow and if it still reports files it is unable to fix, copy & paste this cmd to a Command Prompt (Admin) and press enter.

findstr /c:"[SR]" %windir%\Logs\CBS\CBS.log > %userprofile%\Desktop\sfcdetails.txt

This will put an icon onto the desktop which when double clicked will display the CBS log in Notepad.

Can you copy & paste that into your reply.

Sometimes the files it reports it cannot fix relate to an installed program.

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Scannow still is unable to fix  certain files.

Used the link you provided:  findstr /c:"[SR]" %windir%\Logs\CBS\CBS.log > %userprofile%\Desktop\sfcdetails.txt  in CMD Admin., does not work!

Please advise.

TIA

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It should have done.

Hang on while I perform a sfc /scannow and then apply that cmd.

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I am here!

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Well it worked for me.

Can you copy & paste that cmd again and ensure you highlight all of it before clicking on Copy.

A thought has occurred to me in that the MCT you downloaded could be for version 1903.

Attempting a repair install with that would upgrade you to 1903 and will take considerably longer than a repair install.

I'm in the process of manually updating my other Win 10 machine and it's been running for about 6hrs now and still only on the third phase of working on updates at 48%.

I created a system image first should things not work out, but 1903 is due for release on 11th June though Windows Update.

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Copy and pasted:  findstr /c:"[SR]" %windir%\Logs\CBS\CBS.log > %userprofile%\Desktop\sfcdetails.txt

Still does not work.  Hitting Enter reverts to:  c:\windows\system32

Yes, my Media Tool attempts to upgrade to 1903.  First, clicking on setup.exe in ESD USB rejected and told to remove USB.  Removed and attempted again.  In Microsoft style, waited to the very end to advise that upgrade failed due to "boot error."  Incidentally, repeated crashes of SFCFIX, according to comments via Google says software is problematic.

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It's possible that using an USB can't be used to upgrade to 1903.

Well that cmd should definitely have put an icon onto your desktop.

I have a Win 10 1809 DVD I can send you if you PM me your address with which you will be able to perform a repair install but it would have been preferable to have seen what sfc /scannow was snagging.

You can also boot up with that DVD and navigate to the Install screen to select Repair your computer which will give you the advanced boot options to select Command Prompt.

There you can perform a sfc /scannow where the system files are checked against those on the DVD and hopefully repaired,  but a sfc /scannow can't do all files.

At the cmd prompt enter bcdedit |find "osdevice"

This will give you a partition letter which may not be C:

Using your partition letter instead of the X I have exampled, enter -

sfc /scannow /offbootdir=X:\ /offwindir=X:\Windows

For clarity, that is a Pipe symbol before find and is the uppercase of \

If that reports also that it can't repair some files then you can go ahead with the repair install which may or not resolve the sfc /scannow report as the repair install doesn't touch installed programs or personal stuff.