Without further info, it appears: you have two solutions
1) Use a WINPE boot evironment like Hiren's Boot USB (colliqually known as Hiren's Boot CD) to retrieve your files and then reinstall Windows or 2)take out the hdd/ssd and place it in an external enclosure and retrieve your personal files that way.
Or you use the WINPE boot evironment to fix your windows install although I'm not sure how far you will get with that especially if there are any damaged clusters - presuming it's a standard hdd.
I'd recommend retrieving your data using the PE environment, listening to the hdd if there is any ticking noises. If there are then not even re-installing Windows will help you there (I'm sure you're aware of that already given you're aware of diskpart).
Best retrieve your data and then try a chkdsk /r to identify any bad clusters. If there are run a second pass and if the more clusters appear damaged then it's adios to that HDD.
Or You might get lucky with FIXMBR / FIXBOOT but as I said without further info.... lol.
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