zbook said: View Post
Let's see if this is a possible fix.

1) boot to the Windows 10 iso
2) it may take 5 minutes displaying the windows icon
3) Use the default settings for language, time, currency, and keyboard
4) click next
5) In the left lower corner click Repair your computer
6) click troubleshooting
7) click startup repair (it is expected to fail)
8) click system restore (it is expected to fail)
9) click command prompt
You should see a pop up with title bar: Administrator: X:\windows\system32\cmd.exe
This is the registry backup method:
For each step you must see sizeable file sizes for this to work.
If you see zeros the method will fail.
The command: dir
will be used each step to make sure you are in the proper location and check the size of the files
10) type: C:
11) dir
12) type: D:
13) dir
Choose the C: or the D: drive to proceed. It should be the windows drive and not the USB drive.
For this post I will use C: however you should pick the drive letter that you found that has the windows files on your computer.
The proper drive will display: perflogs, program files, program files (x86), users, windows, etc
14) type or copy and paste: cd \windows\system32\config
It should display: C:\windows\system32\config>
15) type: dir
It should display: bbi, bcd-template, components, default, drivers, elam, sam, security, software, system, vsmidk, journal, regback, systemprofile txr, etc.
All of the file sizes should be sizeable. If it displays zeros then abort.
Make a new directory and name it backup or something similar.
16) type: MD backup
Copy all of the files into this new directory.
17) type or copy and paste: copy *.* backup
It should now display: bbi, bcd-template, components, default, drivers, elam, sam, security, software, system, vsmidk indicating the files were copied.
Change the directory to regback
18) type: cd regback
It should now display: c:\windows\system32\config\regback>
19)type: dir
It should display: default, sam, security, software, system etc
All of these files must be sizeable. If it displays zeros then abort.
20) type or copy and paste: copy *.* ..
It should now display:
Overwrite ..\default? (yes/no/all):
21) type: a
It should now display: sam, security, software, system and that the files were copied.
22) type: exit
23) click turn off your PC
Remove the USB flash drive if you had changed your boot order. Otherwise you can leave it and power on your computer.

Let us know whether or not you were able to perform the steps and boot to windows 10.

again, thank you for that , but I have backed up and have restored the old Regfiles
it does not help..

what is next