With missing files and corrupted boot is kind of hard to recover and the best option will be to reload windows.
Another option I could recommend but cannot guarantee is.
Using your windows installation media.
Do a repair and go to the command prompt.
First option on the command prompt will be to run “sfc /scannow”, without the quote marks.
Second option will be to again at the command prompt you can try each command by itself.
- BootRec.exe /fixmbr
- BootRec.exe / FixBoot
- BootRec.exe / ScanOs
- BootRec.exe / RebuildBcd
Please remember that this are recommendation and not direct Intel How to.