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

Well using this information I have managed to get my PC to start to try and boot in safe mode (it has "safe mode" in each corner of the screen), but it is still stuck with a black screen and just the cursor that I can move with the mouse.

If this is the same as before, then in about a couple of hours it will go back to the diagnostics screen, but not load Windows.

Also, when I manage to get into the command window, everything is in X:/ ....... C:/ is available, but empty.

At this stage I would accept just clean installing Windows 8 (which I thought worked very well), but I cannot even do that as the SSD is now locked.

It is very frustrating. Two machines updated without issue.  A third just will not update.  I have tried literally dozens of times with every suggestion offered.  I was sent a PM by one of the Microsoft engineers with a link to a set of diagnostic tools.  I also received an email from another engineer with the same link.  Since then no further contact.  The problems really don't bother me, but the lack of support and slowness of response is troubling.  Many users began reporting these issues at the preview launch in June, but I never tried installing the preview on anything other than a fresh VM as a test platform.  The update failure I am experiencing now is on a production machine and happens to be my primary machine.  The secondary machine updated easily on the first try.

It just seems strange to me that we are completely unable to drill down and decipher the root cause of the BSOD crash on reboot.  It is also strange that all three were very stable Windows 8 machines, yet the update seems to fail due to a driver issue.  How could a simple incremental update render a working driver buggy?  At this point I have invested all the time I care to trying to resolve this issue.  I will just have to hope that an answer is provided soon. 

Almost 2 weeks and from Microsoft - crickets.

Surface Pro with Windows 8 Professional x64, Microsoft Type Keyboard (version 1), Microsoft Bluetooth Mouse. No other devices connected.

All updates installed except optional Bing Desktop and Bing Bar. No question marks or other errors in Device Manager.

RealVNC, Notepad++, Office 2013 Professional, Legacy 7.5, Intermapper Remote Access, Googloe Earth, Mozilla Firefox, Adobe Reader XI installed.

Same error as others, 0xC1900101 - 0x40017...

I am pretty disappointed too that there has been no fix or even a real acknowledgement. I've tried various things (disabling hardware, BIOS settings, upgraded AMD drivers, clean boot, CHKDSK, updating drivers from the manufacturer --- nothing works).

Same error.

Same silence from Microsoft -- other than some deleted posts.

There is a method of getting the F8 boot menu options back in Win 8: http://www.bleepingcomputer.com/tutorials/enable-the-f8-key-in-windows-8/

My graphics card drivers are totally stuffed if I upgrade them (blank screen, un-responsive machine on boot) and safe mode has been a total life saver as it's the only way I've found to roll them back. Sadly 8.1 insists on installing said new drivers so I can't upgrade to that but at least I'm able to recover 8 which is something.

Not sure if it's helpful to your situation but thought I'd add as an idea at least.