NOTE : your hard disk has 1678 pending sectors (this value is very large and your hard disk should be replaced). Those are sectors that couldn't be properly read and that the hard disk logic is waiting for a write operation to try to remap to a spare sector (if available). According to the Reallocated Sector Count attribute, your hard disk seems to have available spare sectors. A simple disk surface scan won't be enough to force the remap operation. You need a read/write surface scan to remap the sector. The best option should be a tool that knows about what should be read from that sector so that it has some option to apply the best fix to the missing data.