Feature update to Windows 10, version 1709 fails to install

i did try those sfc and dism months ago. there was no error. anyway i did try it again TODAY, here is what i found...

1. DISM

Microsoft Windows [Version 10.0.14393]

(c) 2016 Microsoft Corporation. All rights reserved.

C:\WINDOWS\system32>DISM.exe /Online /Cleanup-image /Restorehealth

Deployment Image Servicing and Management tool

Version: 10.0.14393.0

Image Version: 10.0.14393.0

[===========================96.6%========================  ]

Error: 0x800f081f

The source files could not be found.

Use the "Source" option to specify the location of the files that are required to restore the feature. For more information on specifying a source location, see http://go.microsoft.com/fwlink/?LinkId=243077.

The DISM log file can be found at C:\WINDOWS\Logs\DISM\dism.log

C:\WINDOWS\system32>

2. sfc

C:\WINDOWS\system32>sfc /scannow

Beginning system scan.  This process will take some time.

Beginning verification phase of system scan.

Verification 100% complete.

Windows Resource Protection found corrupt files and successfully repaired

them. Details are included in the CBS.Log windir\Logs\CBS\CBS.log. For

example C:\Windows\Logs\CBS\CBS.log. Note that logging is currently not

supported in offline servicing scenarios.

C:\WINDOWS\system32>

=== i am pretty surprised. there was no such error before===

If you were brave enough, Robert, you could regenerate your entire BCD with BCDBoot. But - in case of catastrophe - don't tell beerus_king. It might scare him off!

(1) That's getting pretty bad, when the computer tells you its system files are corrupt. The only thing, really, that can cure system files are system files.

(a) One cure is an upgrade-install, but we're already having fun doing that.

(b) Try the DISM & SFC duo, in that order, but often they prove to be inadequate, saying there is nothing to fix or saying they did fix it - but still the problem remains...!...

https://support.microsoft.com/en-us/help/929833/use-the-system-file-checker-tool-to-repair-missing-or-corrupted-system

Use the System File Checker tool to repair missing or corrupted system files

And good luck, if they refuse to run or spit out error messages or names of files they can't repair.

(2) Yes

• the ISO or Installation media must match or exceed the OS version that is installed. (The same is true of the Recovery drive.) Yours qualifies. But you can't boot to an ISO unless you burn it to a DVD. You need to boot to it to get to the "Repair this computer" option that will go to the recovery environment. So, either burn that to a DVD (right-click the ISO for the option to burn it) or go back & make a USB version...

https://www.microsoft.com/en-us/software-download/windows10

Download Windows 10 -  Currently, this is version 1709

That is version 1709 now - not v.1703.

(3) Maybe try to make a Recovery DVD (Repair Disc), at "START, Settings, Update & Security, Backup, Go to Backup & Restore (Win 7)" (or ask Cortana for Control Panel, & select Backup & Restore)...

(4) At your ROG site, I think I see it is the ESC key that will get to your UEFI boot options screen. Hold the ESC key as you boot for the boot menu. Then select the DVD or USB Installation media. (Or select the Recovery DVD or USB, if you've been able to make one.) When it starts, remember to click "Repair this computer" at the lower left instead of to install.

Happy weekend.

Before il proceed Id like to clarify some things. This is my first time doing this. how do you do the ff.

"""(a) Boot a Recovery USB drive or a Win 10 Installation media.

      If to the Installation media, choose "Repair this computer" (instead of to install).

(c) At the "Choose an option" screen, click "Troubleshoot > Advanced Options > Command Prompt" 

---- I tried creating first a recovery drive using usb. but the wizard tells me "We cant create a recovery drive on this PC some required files are missing etc""... 

regarding w10 installation media. i have a 1703 ISO file. but my Laptop is at 1607. is that ok?

You did well to set bootmgr to be first in the UEFI boot order screen. The next step will be to regenerate your entire BCD with "BCDBoot". It also will replenish the system partition...

However, I want you first to make a backup BCD file & to check that you can access it in the recovery environment. It isn't good to write files directly to the C:\ root folder. So, first let us make a folder named "BU". Either make it using File Explorer, or enter the following at a Command Prompt (Admin)...

MD  C:\BU

That makes a folder named BU into the C:\ root folder. After that, the /Export will work...

BCDEdit  /Export  "C:\BU\BCD Backup"

After that, check whether you can access it at the Command Prompt of external media. Like I posted above...

(a) Boot a Recovery USB drive or a Win 10 Installation media.

      If to the Installation media, choose "Repair this computer" (instead of to install).

(c) At the "Choose an option" screen, click "Troubleshoot > Advanced Options > Command Prompt".

(d) At the Command Prompt, type:   DIR  C:\BU  /a

                                        Also type:   BCDEdit

Do you see the files listed? If not, I guess try letter D:, in case they have switched. Sometimes, the drive letters are different in the recovery environment. Which letter gave you the files? Did you get output for BCDEdit, (just to prove it is there)?If/when necessary, to recover the backup BCD, you would enter:  BCDEdit  /Import  "C:\BU\BCD Backup"

(e) Close the Command Prompt, & click "Continue" to return.

I can't say it any better than that. After it is done, I'll tell you the rest. But come back with a signed affidavit that it has been done! And I want the broomstick of the wicked witch of the southeast!

We'll have to put a letter onto your system partition, do a BCDBoot, then remove the letter.