Check out my recent article "Use the Recovery Drive Command Prompt to edit the registry or recover data"
http://www.techrepublic.com/blog/windows-and-office/use-the-recovery-drive-command-prompt-to-edit-the-registry-or-recover-data/
It will show you how to access and backup your data when Windows 8 has failed. There are also links to other articles that I have written that will show you how to recover your Windows 8 system
Greg
If have experience with backup may not problem to make use of restore of data selected. Else Use another pc or laptop with your affected drive on an enclosure unit via usb then if posible selec all data that you can reach for backup and copy it locally to your pc or laptop. Then use yuor original drive on your laptop or pc using vendor recovery installed on your affected pc or laptop.or is this not reachable by yourself try F8 key after power up the device. and try recovery from windows either on save mode or last good configuration option if this not work find your software original and start all over from zero.. good luck ....HNDay
How to get back your data from MS windows 8?