Repair Windows 8/10 Startup Failing

Bootrec /scanos gives [1] c:\windows OK

Bootrec /RebuildBCD /Y gives the requested system device could not be found

BCDEdit gives the boot configuration data store could not be opened. The requested system device could not be found.

DiskPart select volume 1 active gives The ACTIVE command can only be used on a fixed active MBR disk

SFC /scannow /offbootdir=D:\ /offwindir=D:\windows Windows Resource could not perform the requested operations

Now all of this may appear to be an issue with your windows installation but you need to check something more simply accessed.

What is the boot order in your BIOS settings - you may need to put the HDD first and reboot to see what happens. I know you have checked this first but Windows 8 & 10 are not as predictable as 7 and earlier versions and sometimes the disk is accessed and then the system starts looking for data on the first item in the boot drive list and it all goes wrong.

If BCDEdit cannot access the files but you can browse to the C:|boot folder then you need to check the boot order in BIOS or your UEFI settings.

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You can solve this by repairing the EFI Folder which you can read about here: Repair EFI partition Windows 10 

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