I just went through this nightmare on a Win 8.1, 64 bit system and finally had to refresh Win 8.1, which sucks because it strips out drivers and any downloads, some times leaving behind partial files or corrupted dlls. I tried everything - bcdedit commands didn't work, bootrec commands didn't work and the auto repair is a joke.
While reinstalling drivers, I stumbled on this bit of information that may help others from losing data. This may or may not work but it won't hurt an already compromised system. I was able to run both DISM and SFC from safemode after refreshing the system.
If the Automatic Repair Loop is running it is very possible that the registry and /or files have been scrambled.
If you run the Windows Deployment Image Servicing and Management (DISM) and System File Checker (SFC) tools, they will scan the integrity of the Windows image and all protected system files - replaces corrupted, damaged and incorrect versions.
To repair, place the cd in system and boot from it following the on screen prompts.
When the "Install Now" screen appears, look to the bottom left and choose "Repair Your Computer"
The next screen heading states "Choose An Option" , select "Troubleshoot," then "Advanced Options," then "Command Prompt"
At the Command Prompt, type the correct drive letter + : for your system (usually C, D or E)then press the "enter" key
You should see C:>
Type without quotes, "DISM /Online /Cleanup-Image /RestoreHealth" and press the "Enter" key.
**While running DISM the process will appear to pause or stall at 20% - after a few minutes the operation will continue (depending on the size of your hdd and ram).
Once DISM has finished, run the SFC scan:
At the C:> drive prompt, type without quotes "SFC /SCANNOW" and press the enter key.
when done, type "Exit" and press the "Enter" key.
Restart system.
If you are not in the auto loop and can boot into windows, safemode is accessible by pressing the windows key + r - this will bring up the 'run' screen. Type without quotes "msconfig" - then choose the Boot tab then click on safeboot and network. Restart.
Can also access Command Prompt (Admin) by pressing Windows Key + x - brings up power menu - select Command Prompt (Admin).