Hello Charles,
First after making sure you have a complete backup of any data you care about. You should test the Hard Disk Drive or the Solid State Drive HDD/SSD to make sure it is not failing. You can do this by downloading a trial of HD Tune Pro from their website here. Once you have the program installed, you can then launch it and navigate to the health tab and look for any red or yellow warnings. If all looks well then you most likely have data corruption on your Storage device. You can run a check disk by following the directions here. If Checkdisk finds nothing to repair you can now the DISM tool to repair the Windows installation.