Error: We couldn’t complete the updates, Undoing changes. Don’t turn off your computer.

mr. stem,

See this site on how to contact Microsoft: http://www.microsoft.com/surface/en-us/support/contact-us/

I just tried it myself using these options after selecting Surface Pro and the waiting time was only 7 mins.

Harry,

With regard to your last point regarding CCleaner, please see this article: http://chris.pirillo.com/are-registry-cleaners-safe-to-use/

... according the Surface site, there weren't any updates released in June ...

Well, there was definitely a fresh build of KB2919355 available to my Surface Pro as of 17 June 2014, and I have now made two separate attempts at installing it.  (You can guess where this is headed.)

Before I started, I removed all USB devices, and also the SD card which I use to store photos and MP3s (as the C: drive on my Surface Pro (1) is only 128GB) after first removing it from the relevant libraries and also as the usual source for my desktop images.

The first attempt had downloaded up to about 6%, and next moment I looked it was installing.  It then went all the way through; two restarts later it failed configuring Windows Updates at 100% and then painstakingly rolled the whole thing back for the umpteenth time.

At this stage, I decided I had to give the DISM commands another try, having read some posts suggesting that people have had more luck with them recently.  These commands seemed to take longer than on previous occasions and, as per the trace below, you will see that the last command completed with the encouraging message, 'The component store corruption was repaired.'.

So I then made my second attempt, and this time it downloaded to at least 92% before saying it was installing.  (I have no idea if this difference is significant, or if I should even have expected it to reach 100% first.)   It then went all the way through, I even had an idea that the progres bar made it further across this time; but, two restarts later, it again failed configuring Windows Updates at 100% and then painstakingly rolled the whole thing back for the umpteen+1th time.

My next step is to re-open my support case with MS which was suspended while I was travelling and to push for access to an 8.1 Pro ISO from which I can attempt the in-place repair.  I have seen nothing yet which explains why I should have to pay to access to this (when I already have this system legally installed on my system) and I am ready to make more of a fuss this time after wasting another half day on this debacle.

--------------- DISM trace follows -------------------

C:\WINDOWS\system32>DISM /online /remove-package /packagename:Package_for_KB2919

355~31bf3856ad364e35~amd64~~6.3.1.14

Deployment Image Servicing and Management tool

Version: 6.3.9600.16384

Image Version: 6.3.9600.16384

Processing 1 of 1 - Removing package Package_for_KB2919355~31bf3856ad364e35~amd6

4~~6.3.1.14

[==========================100.0%==========================]

The operation completed successfully.

C:\WINDOWS\system32>DISM /online /cleanup-image /startcomponentcleanup

Deployment Image Servicing and Management tool

Version: 6.3.9600.16384

Image Version: 6.3.9600.16384

[==========================100.0%==========================]

The operation completed successfully.

C:\WINDOWS\system32>DISM /online /cleanup-Image /restorehealth

Deployment Image Servicing and Management tool

Version: 6.3.9600.16384

Image Version: 6.3.9600.16384

[==========================100.0%==========================]

The restore operation completed successfully. The component store corruption was

 repaired.

The operation completed successfully.

I finally backed up everything, used DVD recovery media to start all over again, did all updates, then reinstalled programs and data.  Now everything works and computer is decidedly faster.  I am not an IT professional, but I can think of a few things that may have contributed to not being able to do The 8.1 KB2919355 updates.  It may be that others with these problems have done some of the same things, so if we can find a common thread,perhaps we can avoid this in the future, or Microsoft an come up with a fix:

1.  I bought my Lenovo Yoga 13 with a 256 gig ssd.  After manipulating the partitions, I lost my restore partition although the unit worked properly.  Then I bought a 512 gig and used EaseUs Todo Backup and created an image of the entire 256 gig and restored it to the 512 gig.  I also bought the DVD media from Lenovo so I could once again have a factory fresh system if I desired.  I used that media on the 256 gig hard drive and used diskpart to compare the factory partition structure ("detail part" command) to what EaseUs Todo left me on the 512 gig.  Although the 512 gig system worked, several of the partitions had changed "attribute" values and some had drive letters and were not hidden as originally they were.  Also they had offsets that were not original.  I used diskpart to reconfigure the partitions to match the factory, but the offsets were definitely different and I did not change those because I did not want to risk making the drive unbootable.  So EaseUs did a poor job of faithfully restoring the partition structure and may have caused problems that did not show up until KB2919355.
2.  I installed both my 256 and my 512 gig SSDs in my Lenovo Yoga 13.  The unit recognized and assigned drive letters to each. When the update form 8.0 to 8.1 happened, it failed time and again.  When I removed the 256 gig drive, the update worked as it should and I again put the 256 gig back in.  I wonder if having both drives in there may have compromised some update(s).  After all, 8.1 would not even install with it, so couldn't some other update have installed improperly?
3.  I used Ccleaner to clean the registry.  Is it possible that ccleaner "cleaned" something that should have been left?

@Xircal, I wonder if the updates were only made to the Surface Pro version of the update.

You might be right, but according the Surface site, there weren't any updates released in June at all: http://www.microsoft.com/surface/en-gb/support/install-update-activate/pro-update-history