Has anyone ever had his happen: Today, my Dell desktop with Windows 10 ( recently upgraded from 7 a few months ago), went into some kind of repair/ reinstall mode, with various basic and advanced options to try. To get back to a point of using again I had to do a complete reset/ reinstall of Windows 10, that  kept all my files, but every program/app that did not come with that computer goes!!! It's working great, but now I have to completely reinstall my Sonar programs, and all other apps/ programs. !!! 

I hope you have a backup strategy.. next time your data may not be so lucky :)

Anyway every 3 years or so I often wipe and reinstall Windows.. yup self inflicted.

Ouch!
 
Once you get it sorted and working again, recommend setting up and using a disk imaging program.
 
One example which I can vouch for is Macrium Reflect Free.  https://www.macrium.com/reflectfree
 
Set that up and schedule regular system drive image backups to a secondary or external USB drive and you are covered if your system ever goes haywire or fails to boot.  I take a daily image and keep daily, weekly and monthly copies of my system.  Macrium has a wizard that creates the rescue media automatically that you can boot from to restore an image if necessary.
 
If you do this, the likelihood of ever needing to install Windows or your apps again is slim...