Hey and welcome to my video where i help you to get rid of that error, with no data loss.
Please leave a like and comment.;)
Every command needed (exact order):
$ bootrec
$ bootrec /fixmbr
$ bootrec /fixboot
$ bootsect /nt60 sys (if used, type bootrec /fixboot once done)
$ bootrec /scanos
$ bootrec /rebuildcbd
$ exit
I hope this helped you.
Contact me if you need anything or need support:
Telegram - t.me/Justinnn1337
Discord - Justinnn#6270
Hope you have a great day ! :)