If SFC could not fix something, then run the command again to see if it may be able to the next time. Sometimes it may take running the sfc /scannow
command 3 or more times to completely fix everything that it's able to.
If not, then you can attempt to run a System Restore
using a restore point dated before the bad file occured to fix it. You may need to repeat doing a System Restore until you find a older restore point that may work.
If still not, then you can use the steps in the TIP box in the OPTION THREE
section below to manually replace the files that SFC could not fix.