Was the windows 10 iso made from the Microsoft website?
If not please find a flash drive that you can format (8GB or larger)
Make a bootable windows 10 iso:
Download Windows 10
Was system restore attempted?
Did it fail?
If it was not attempted that should be the first step (start with the oldest restore point and move forward in time trying each restore point.)
If system restore failed or if there were no restore points move to the next step.
Was startup repair performed?
If not, then attempt startup repair.
If both system restore and startup repair fail move to command prompt.
The command prompt commands will attempt to :
1) repair OS
2) repair drive file system
2) repair boot
3) repair registry
If these steps fail the next step will be boot recovery.
Using a bootable windows 10 iso open command prompt > Administrator: X:\windows\system32\cmd.exe > Sources X:>
1) type: bcdedit | find "osdevice"
(look for the drive letter for the partition)
2) type: C:
type: dir
3) type: D:
type: dir
(look for the drive that has windows and users)
4) type: X:
type: Sfc /Scannow /OFFBOOTDIR=G:\ /OFFWINDIR=G:\Windows
(change the letter G to the drive letter for the partition displayed in step #1)
This may take some time to run.
5) type C:
6) type: Chkdsk /f
7) type X:
9) type: bootrec /scanos
10) type: bootrec /fixmbr
11) type: bootrec /fixboot
12) type: bootrec /RebuildBcd
13) Use a camera or smart phone camera to take pictures of the commands and results and post an image into the thread
14) reboot
15) report into the thread whether you were able to boot to wall paper/splash screen or whether there was an error message and error code or a failure to boot without error message and code.
If the above fails plan registry backup repair (these are windows advanced troubleshooting menu commands)
If the registry repair fails find another flash drive that you can format and make a boot rescue drive:
Windows 10 Recovery Tools - Bootable Rescue Disk - Windows 10 Forums
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