Looking for some advice here, going to keep it nice and simple.

I am trying to fix a friends Windows 8.1 install, she updated it 3 weeks ago and ever since it has failed to boot.

It loads the Windows Start Up Recovery screen or goes in a loop of trying to diagnose the issue and then boot up, is fails to do it.

We have tried using all the options in the recovery screen they are not working as it will not accept any of the passwords that she was likely to have used on the computer.I have also tried to bot it into Safe Mode and use the advance options to see if it give us any idea to what the problem is.

Is there anyway this can be fixed?