Which version of Windows are you using and have you performed a sfc /scannow ?
If using Win 8.1 or Win 10 then enter these cmds before the sfc /scannow -
dism /online /cleanup-image /startcomponentcleanup
dism /online /cleanup-image /restorehealth
The first dism cmd will clean out obsolete Windows Updates from the WinSxS folder, although Win 10 does this auto after 30 days, but there have been a couple of recent Win 10 updates.
Try the repair program again in Safe Mode after those cmds.