How to Repair Boot issues on Windows 8 Developers Preview
There might be cases where your Windows will not boot, it might go in bootloop. Such cases you could run “Automatic Repair” from the Windows Recovery Menu.
Press F8 while booting the system to go into Windows Recovery Menu. Unlike other version Windows 8’s recovery menu has Metro UI style.
Click on Troubleshoot
Click on Advance options to get into Automatic Repair menu
Now click on Automatic Repair, now you system will restart and take you to the Automatic Repair menu. You have to select you account.
Once you select you account it will prompt you for your password, Enter the password and click “Continue”
Now Windows will search for problem and try to correct it.
Once it’s done it will ask you to reboot your system. If it fails then to run it upto 3 times.
Hope this helps!