Windows 11 Corrupt System Files
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This morning, as is usual on the second Wednesday of the month, there was a major update for Windows 11. As usual, I ran sfc /scannow after the update, to check for corrupt system files. As usual after an update, sfc reported it found and repaired corrupt files! Why do I often end up with corrupt system files after major updates? By the way: I run the following two system commands as admministrator to check system files: DISM.exe /Online /Cleanup-image /Restorehealth followed by: sfc /scannow
Ok, I have had my coffee, so you can all come out now!
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This morning, as is usual on the second Wednesday of the month, there was a major update for Windows 11. As usual, I ran sfc /scannow after the update, to check for corrupt system files. As usual after an update, sfc reported it found and repaired corrupt files! Why do I often end up with corrupt system files after major updates? By the way: I run the following two system commands as admministrator to check system files: DISM.exe /Online /Cleanup-image /Restorehealth followed by: sfc /scannow
Ok, I have had my coffee, so you can all come out now!
Updates pushed out on Patch Tuesdays can reasonably be expected to replace OS files. SFC compares your OS files with, what, OS files as they exist on the distribution media? If so, then it seems obvious it *would* find mismatches. But does that mean the new files are, in fact, corrupt? Are you not in effect undoing what the patch is intended to do?
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Updates pushed out on Patch Tuesdays can reasonably be expected to replace OS files. SFC compares your OS files with, what, OS files as they exist on the distribution media? If so, then it seems obvious it *would* find mismatches. But does that mean the new files are, in fact, corrupt? Are you not in effect undoing what the patch is intended to do?
After the files have been repaired, I run "check for updates" and it reports I am up to date - with the repaired files! I don't have any indication that the repair will undo the patch? Difficult to be sure!
Ok, I have had my coffee, so you can all come out now!
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After the files have been repaired, I run "check for updates" and it reports I am up to date - with the repaired files! I don't have any indication that the repair will undo the patch? Difficult to be sure!
Ok, I have had my coffee, so you can all come out now!
I can see how SFC could roll back an update's OS files, but Windows Update itself might not be aware the files have subsequently been replaced, and so - when checking for updates - all WU can tell you is that updates *have* been installed and it'll happily report everything's hunky dory. I don't know if MS has ever fully documented what's supposed to be taking place...as such, if I have to run SFC after updating the OS...is the OS still up to date? Who knows, I avoid using SFC as its expected behavior under those circumstances is dubious at best (IMNSHO)...
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I can see how SFC could roll back an update's OS files, but Windows Update itself might not be aware the files have subsequently been replaced, and so - when checking for updates - all WU can tell you is that updates *have* been installed and it'll happily report everything's hunky dory. I don't know if MS has ever fully documented what's supposed to be taking place...as such, if I have to run SFC after updating the OS...is the OS still up to date? Who knows, I avoid using SFC as its expected behavior under those circumstances is dubious at best (IMNSHO)...
Maybe run DISM to update the windows media that SFC uses before you run SFC? Check out the following video for a description: Easily fix broken Windows files now with System File Checker - YouTube[^]
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This morning, as is usual on the second Wednesday of the month, there was a major update for Windows 11. As usual, I ran sfc /scannow after the update, to check for corrupt system files. As usual after an update, sfc reported it found and repaired corrupt files! Why do I often end up with corrupt system files after major updates? By the way: I run the following two system commands as admministrator to check system files: DISM.exe /Online /Cleanup-image /Restorehealth followed by: sfc /scannow
Ok, I have had my coffee, so you can all come out now!
Hip shot here... The way corruption is often detected is to compare the CRC of the known good file to the CRC sitting on disk. In the case of an update, it's maybe reasonable that the local table of known good CRCs doesn't contain the most recent information. It might be that what is happening isn't changing the file to fix the corruption but rather updating the CRC in the known good CRC table by fetching the latest known good CRC from an online resource. I don't know, but this makes way more sense than windows update writing bad data to disk on the regular. Another possibility is that you have a failing drive or drive controller.
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Hip shot here... The way corruption is often detected is to compare the CRC of the known good file to the CRC sitting on disk. In the case of an update, it's maybe reasonable that the local table of known good CRCs doesn't contain the most recent information. It might be that what is happening isn't changing the file to fix the corruption but rather updating the CRC in the known good CRC table by fetching the latest known good CRC from an online resource. I don't know, but this makes way more sense than windows update writing bad data to disk on the regular. Another possibility is that you have a failing drive or drive controller.
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In the case of an update, it's maybe reasonable that the local table of known good CRCs doesn't contain the most recent information.
I'd think the update process should handle this. When I deploy new embedded builds to products, the process includes updated CRCs. Then again, we are discussing Microsoft and Windows 11, so, YMMV. OP - why do you do this after updates? Is there something wrong after updates? I'm typing this on a 5 yo laptop running Windows 10 Pro that has been updated so many times I've lost count. I've never run a disk check after updates.
Charlie Gilley “They who can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety.” BF, 1759 Has never been more appropriate.