"Couldn't update to Windows 8.1 - 0xC1900101 - 0x40017"

This sounds interesting, so I ran the setup again and eventually the windbg.exe points to "disk.sys"!! I guess there is a kind of incompatibility with my SanDisk SDSSDH2256G disk drive?? The driver "disk.sys" is manufactured by MS and I have no idea on what to do next. 

Thanks MS for helping us!!!

if you have a solid state express drive it may be the driver for that, or an incompatibility with the program that manages it.

My first two attempts a couple of weeks ago failed (same error code everyone else has seen).  My first two attempts were a couple of days after my purchase of the computer (HP Envy 700-056 Desktop) and after installing all the available Microsoft updates.  I noticed that there have been several updates to Windows 8 installed on my computer since then, so I decided to try again last night, and it worked!  I didn't have to do anything special.  I simply re-downloaded Windows 8.1 and installed it without any further problems.  Goodluck everyone. I hope you can get it installed soon too.

That seems to be a good contribution to our struggle of getting stubborn Windows 8.1 installed. It points out that there might be some data on what went wrong. Also in that folder (C:$WINDOWS.~BT) one can find a number of error.log files. Unfortunately they are too cryptic (and frugal) for even people with some PC experience to figure out what was wrong. We can only hope this:

1. Either Microsoft redesigns the error logs. Is would be very simple to generate something like this:

• engage driver XXX - success
• engage driver XXY - success
• engage driver XXZ - failure
• Windows instalation halted. etc

2. Or experienced users try to courteously design some widget to interpret the error logs and the crash dump files.

Otherwise, this fight to cheat Windows 8.1 into getting installed is becoming stupid. Of course, there are multitude of configurations, but this installation is very poorly designed. That shows the increasing incompetence of the younger generations of programmers.

These installation errors occur mainly because some software or hardware component is not to the liking of Windows 8.1. -  a driver, some registry entry, a video/sound card, an external device (disk, USB).... It really is not hard to modify the installation kit towards pointing exactly to the device in question.

Sometimes, suspending/removing the problematic item will let Windows 8.1 get installed and reapplying the item will generate no new problem. Other times, reapplying that item will lead Windows 8.1 into a BSOD, so that item might be used never again.

My particular case was an older SB Live (sound card). Windows 8 already had a problem with that. I could only identify that because of the BSOD type: BAD_POOL_HEADER. Removing the sound card, allowed Windows 8.1 to install, but replugging it made Windows 8.1 not start. I "cheated" both Windows 8 and 8.1 with an adapted 3rd party driver (kX Audio Driver).

WOW. page 56 and how many months later we are still dealing with failed installs. What, is Microsoft seeing we are fixing it ourselves and just brushing fixing the actual code under the rug?

Very good idea Sorein, that would definitely help. As far as developing our own program to decode it, most likely near impossible, as you would have to have a Microsoft error code dictionary. And don't punish the developers too hard. The real fault most likely lies in Microsoft trying to shove this out too soon before the developers were finished.