Fixing Boot Errors in Windows 8

Step 1: Boot from a Windows 8 Recovery Media...

Step 2: Select Trouble Shoot -> Advanced Options -> Command Prompt
         
Step 3: Type in the commands below, in command prompt one after the other

            bootrec /scanos

            bootrec /rebuildbcd

            bootrec /fixmbr

            bootrec /fixboot


Step 4: Reboot

Try these if  automatic startup repair and system restore fails.