Why won't my system restart after it runs its scan

Are you talking about the filesystem scan? If you are than your hard drive is probably broken. You can use any laptop hard drive as a replacement and there is a tool on sony's website to install the system files to your drive via a Universal Drive Adapter

You can find laptop hard drives anywhere here is a link to an amazon page. You can find an assortment of drives and chose what fits your needs as far as storage space. http://amzn.to/2cK5z1t