A reinstall is going to be required -- before undertaking that process, verify that the storage drive is not failing.  F12 at powerup - run the extended diagnostics on the system. If you require further assistance, post the result of the diagnostic (record any error such as 2000-0142, -0151, etc.) and post the model number of the system (inspiron 3593, 3501, etc.).  
Computer stuck on auto repair and will not repair  
Auto Repair not working