Troubleshooting and Fixing Windows 8's Boot Configuration
 

Windows 8 received a decent amount of enhancements on the desktop side that I tend to appreciate versus running Windows 7. One such area of improvement is notification management and how it handles updates and system restarts. Running the final version of the OS for a few months now, it's been a painless affair until this past weekend.

Unable to boot all of sudden, after some troubleshooting I settled on the idea that it wasn't a hardware problem. With a long history of dual booting different versions of Windows over the years, finding a corrupt MBR, boot sector, or Boot Configuration Data (BCD) is nothing new, but it took me longer than usual to come to a solution.

http://www.techspot.com/guides/630-windows-8-boot-fix/