Hi MF. I'm Greg, an installation specialist, 10 year Windows MVP, and Volunteer Moderator here to help you.
At any point you can rescue your files using this method:
http://answers.microsoft.com/en-us/windows/wiki...
Everything else possible to get WIndows 10 to start is here:
http://answers.microsoft.com/en-us/windows/wiki...
But I'd save time and do the gold standard Clean Install in this link which compiles the best possible Install of Windows which will stay that way as long as you stick with the tools and methods given, has zero reported problems, and is better than any amount of money could buy:
http://answers.microsoft.com/en-us/windows/wiki...
To create bootable Windows 10 Installation Media (on another PC if necessary) install Media Creation Tool and follow the directions in the middle of the download page here:
http://windows.microsoft.com/en-us/windows-10/m...
Insert media, boot it by powering up PC while pressing the BIOS Boot Menu Key for your PC maker given in this chart:
https://www.sysnative.com/forums/hardware-tutor...
If the media won't boot you may need to enter BIOS/UEFI Setup (pressing key given in chart in link above) to turn off Fast Boot or Fast Startup first.
Choose the boot device as a UEFI device if offered, then on second screen choose Install Now, then Custom Install, then at the drive selection screen delete all partitions down to Unallocated Space to get it cleanest, select the Unallocated Space, click Next to let it create and format the needed partitions and start install - this makes it foolproof.
There is a step to rescue your files first using the booted media if you don't have them backed up:
http://answers.microsoft.com/en-us/windows/wiki...
You will get and keep the best possible install to the exact extent you stick with the steps, tools and methods in the linked tutorial. It's a better install than any amount of money could buy and a great learning experience that will make you the master of your PC because you will learn everything that works best and how to apply it with your own hands.
I hope this helps. Feel free to ask back any questions and let us know how it goes. I will keep working with you until it's resolved.
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