Windows 8 includes a recovery feature called Automatic Repair that attempts to automatically diagnose and fix common issues that may cause Windows 8 to not start properly. Automatic Repair will start automatically when Windows is unable to start properly. Once started, it will scan various settings, configuration options, and system files for corrupt files and settings. If it detects anything, it will automatically attempt to fix them for you.
To access Automatic Repair in the Windows Recovery Environment you need to go to the Windows 8 Start Screen and type Advanced. When the search results appear click on the Settings category as shown below.