I'm afraid I'm going to have to insist that it is installed. Where did you look for this update?
Users have reported this very issue and the only common denominator is that Windows update. We had one user who went so far as to test the theory by running sfc without the update installed, then installing it and running sfc again...then uninstalling the update and another run of sfc.
In each case, users report the very same issue as yours. Without the update, the sfc runs fine and either will have been reported to have repaired something or completed the run without having found any missing or corrupt files. However, once one installs the update, the sfc runs and the same complaint of corrupt irreparable files is logged. The same user uninstalls the update, runs sfc once more to report that the scan completes with no issues.
On your next reply, let us know what other issues remain...if you are unable to locate the update, I would more than likely consider next, a recommendation to either reformat/reinstall or try a repair install. As it is, if your protected files are questionable as to a sfc finding, I would not want to trust the system...period.