"Couldn't Complete Update, Undoing Changes" with Windows 10 Cumulative Update KB3105213

Please provide a copy of your System Information file. To access your System Information file select the keyboard shortcut Win+R, type msinfo32 and click OK . Place the cursor on System Summary. Select File, Export and give the file a name noting where it is located. Click Save. Do not place the cursor within the body of the report before exporting the file. The system creates a new System Information file each time system information is accessed. You need to allow a minute or two for the file to be fully populated before exporting a copy. Please upload the file to your OneDrive, share with everyone and post a link here. Reports in normal mode preferred. Please say if the report has been obtained in safe mode. If the report is in a language other than English, please state the language.

Please upload and share with everyone fresh copies of your System and Application logs (two files) from your Event Viewer to your One Drive and post a link here. You can remove the earlier copies of the logs from your OneDrive.

To access the System log select the keyboard shortcut Win+R, type eventvwr.msc and press the ENTER key. From the list in the left side of the window select Windows Logs and System. Place the cursor on System, select Action from the Menu and Save All Events as (the default evtx file type) and give the file a name. Do the same for the Applications log. Do not provide filtered files. Do not place the cursor in the list of reports before selecting Action from the menu. Do not clear logs whilst you have a continuing problem.

For help with OneDrive see paragraph 9.3:
http://www.gerryscomputertips.co.uk/MicrosoftCommunity1.htm

I also have this issue. The all important error-code 0x80070011 means:

ERROR_NOT_SAME_DEVICE:

  The system cannot move the file to a different disk drive.

This is probably the real reason behind your (and my) problem. And the details of how Windows is updating important files during the Boot-process is pretty messy and hard to understand. But the files  %WinDir%\Logs\CBS\cbs* gives some clues. Like:

...

Configured poqexec to pend to SetupExecute.

Running poqexec with: C:\WINDOWS\System32\poqexec.exe 

    /noreboot /transaction 4732 /display_progress \SystemRoot\WinSxS\pending.xml

Waiting for poqexec.exe to complete...
Failure in poqexec.exe while processing updates. [HRESULT = 0x80070011 - ERROR_NOT_SAME_DEVICE]

...

Status = STATUS_NOT_SAME_DEVICE,

Operation = HardLinkFile, DiagString =  [l:412{206}]"\SystemRoot\WinSxS\amd64_presentationcore_31bf385....,

  \??\f:\ProgramFiler\Reference Assemblies\Microsoft\Framework\v3.0\PresentationCore.dll"

....

The last error example shows poqexec trying to copy from c:\Windows\WinSxS to %ProgramFiles% which is not on the same partition. Did you perhaps moved some important Windows files from c:\Program Files\ to x:\ProgramFiles\?

More details are in %WinDir%\WinSxS\pending.xml. Note there can be many of those too. One for each update attempt (?).

Some MS Support Engineer correct me on this, but AFAIK, the poqexec program is a native process that doesn't know how to handle hard-links (Junctions and Reparse-Point) since it runs very early in the Boot process. Hence the ERROR_NOT_SAME_DEVICE in the rename or copy operation it's trying to do.

poqexec = "Primitive Operations Queue Executor". Meaning very primitive.