windows 8.1 download will not update past 50%

Someone below mentioned that 80% of users have no problems.

If he is correct, wouldn't you think that a 20% failure rate would be a bit more excessive than Microsoft's QC people would find tolerable?  I mean, really!

But for me, I am on my third install of 8.1 now.  On the first, on a secondary computer on which we do not depend, I installed it over 8.1 Demo and it completed normally (but, as I was warned, hosed all of my applications).  The Demo install, however, initially had this same problem of aborting around 50%, a problem I solved by downloading the .iso file and installing from that -- and it did NOT hose all my apps at that time.

My other two machines, both "production" machines on which we rely (one is a very high-end homebuilt and the other a similarly high-end HP laptop), both had this (and numerous) other problems with this install over Win 8 Pro with Media Center, aborting at roughly 50% and returning error code 0x80240031.  After spending a whole day on the phone to Microsoft Support, including two escalations, I finally got it installed on my home-built.  But after performing all the usual things to try to get past this (complete removal of anti-malware, sfc /scannow, update everything to current, clean boot, removal of all spyware, disk scan) I'm fresh out of ideas.  I get the same failure at the same point whatever I do.

So my own personal failure rate in real life to install this from the store over Win 8, whether demo or production, is 100%, and is 75% overall.  And please note that I am a computer professional, formerly the Internet Services Administrator, IT Security Administrator, and lead Unix system engineer at a major Federal agency particularly renowned for its technological prowess, and I have been working with Microsoft's operating systems since the first versions of IBM/Microsoft's PC DOS.

Whoever is responsible for this at Microsoft should find him- or herself on unemployment forthwith.

I'm in a similar situation - I have been in the software industry for 40 years now, used to manage IT services for a large research campus, and I develop software for the Microsoft platform, so you could say I am a seasoned pro with a vested interest in Windows being successful.

Running Windows Update used to be a straightforward thing that one did to ensure PCs were stable and secure. Last year that all changed - first I had a bunch of XP machines where I just couldn't seem to get the updates done, and just over the last couple of weeks have tried to marshal a fresh Vista install thru the updates, and finally gave up and bought the 8.0 upgrade, intending to install that and then do the (simple, I thought) upgrade to 8.1.  Long story short, I've burned thru about 30GB of data, lost track of the number of attempts at the 8.1 upgrade, surely at least 10, even lost track of the number of re-installs of Win 8 (3? 4?).  I start to believe that whoever is currently managing the Windows Update platform for MS was planted there by Apple and Google to make sure that nothing works. How else can I explain the wall-to-wall frustration that Windows Update now causes?

A number of my failed attempts were based on a sequence where I tried to short-circuit the Windows Updates by installing just the one (KB 2871389) that is needed to get 8.1 to appear in Store. When that didn't work I ended up installing all the others, but that still never led to a solution.

In my case the magic recipe that worked for me was:

1. Reset Windows 8 (effectively a reinstall, maybe a tad quicker).
2. Turn off Defender.
3. Check for Windows updates, try to install all the Important updates. In my case they all failed with 0x80248007. I accepted the 'Try again' option and they worked OK. Go figure.
4. After each batch of updates, restart, check again for updates, apply updates, until no more updates.
5. Proceed to Windows Store and download 8.1
6. After 8.1 setup complete, turn on Defender