Preparing automatic repair

[chez]

I know this has been answered to a degree before but...

my Pc suddenly went into Preparing Automatic Repair whilst I was working on it. I have tried the tests and they all Passed.  I tried going into F11 for system restore, but it goes straight back to black screen saying Preparing Automatic Repair.  Left it on for hours. No joy.  Turned off and on etc no joy. 
I get a blue screen sometimes saying ... We will restart your pc for you. Go to ...blah blah blah. 
nothing is working at moment. Don’t want to try a complete reset as cannot really afford to lose all info on it! 
anyone have any ideas please? 

[TheOldMan]

While it is not posted which Windows version is being used, you can use Windows 10 install media to repair Windows 8, 8.1, and 10.  See here for the media download:

https://www.microsoft.com/en-us/software-download/windows10

With a working PC, scroll down to the "Using the tool to create installation media" and follow the directions.  Then boot the problem PC to this new media and pick repair instead of install.  If this fails to fix the problem, then you can use this media to reinstall Windows 10.  Assuming you wish to save your data from the drive before doing that, come back here for help.