...and the boot configuration database remains intact, then you should be able to regain access to Windows 8 dual-boot. However, how you go about that is another matter and I'll have to investigate and see what I can find.

If you want to see what the Boot Configuration Data looks like, check out the article Remove Windows 8 from a dual-boot configuration
http://www.techrepublic.com/blog/window-on-windows/remove-windows-8-from-a-dual-boot-configuration/6571

If you decide to experiment, MAKE SURE that you BACK UP your important data before you do anything.