You should download the latest version of Defraggler and install it. If the problem shows again then try the Error Checking tools of Windows. Initiate the program and restart your PC. After restarting the computer windows will check your hard disk errors. Now, run Defraggler and see the health of your drive.
First Check your hard disk health and I recommend PassMark BurnInTest software for it and check it. May be few bad sectors will be there and recover it by recovering tool by founded on in internet. Then you can defrag your hard hand, Try those easy steps.