Window 8.1 automaitc repair loop

So, i went to turn on my pc the other day and it went to automatic repair and told me the issue could not be solved "log file: D:\Windows\System32\Logfiles\Srt\SrtTrail.txt ". I have tried to refresh my pc and it says "the drive where windows is installed is locked". I have tried to resent my pc and it says "unable to reset pc. A required drive partition is missing." My pc is relativly new so i have not yet created a restore point. I have a USB with windows 8 on it, however the disc i used to download windows 8 is not with me. I also have my product key for windows. I have tried to go into advanced options and change my startup settings however when i click restart the computer just goes right back to the automatic repair. Im not really sure what to do at this point.