This problem started a few weeks ago : PC randomly freezes (maybe once in a week or more), becomes completely unresponsive and has to be powered off. After that windows can't be booted. It tries to repair the system but always fails. The only thing that helps is plugging in an USB drive with windows image and entering these commands in command prompt:
bootrec /FixMbr
bootrec /FixBoot
bootrec /RebuildBcd
After this windows starts working. I've tried formatting my SSD and performing a clean installation a few times but still the problem persists. I've checked SSD with Samsung