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

Just for the record (and with hope that someone who is actually working on resolving the issue reads), as I wrote in the  0xC1900101-0x30018 thread - I too suspect the Ralink RT3290 wi-fi card. Anly that left in my case, as I've spend last two days trying different solutions on my HP G6. If that'd be a PC, removing the card physically would be not an issue for me, but that's a laptop, so I'm not going to do anything more to it than rchanging HDD/RAM, and I think that is already more than majority of users is prepared to do... For most people even opening the damn thing is too much.

So, as my last attempt to upgrade is now in progress, and if it will fail - we, people that don't have how to disable that stupid card (my BIOS lack this feature), will have to wait for the right driver to appear in Windows Update, aor HP servers. That's the only option. I just don't see why it takes so long for such an obvious solution found by mere amateuers...

I have the same problem with an off the shelf HP Envy M6 laptop.  All drivers are up to date and no devices are attached.  No explanation why it failed other than the 1900101 error.

Doesn't look like MS really know how to fix it given it's not several months since the problem first surfaced.

I agree that MS doesn't know how to fix it (or care to) -- however, they knew about this when the beta came out and did nothing about it. And we are to believe they listen to their customers?

I have the same problem with an off the shelf HP Envy M6 laptop.  All drivers are up to date and no devices are attached.  No explanation why it failed other than the 1900101 error.

Doesn't look like MS really know how to fix it given it's not several months since the problem first surfaced.

I'm also considering going back to windows 7… I just literally don't have time for all this.

What's interesting about all this is that MS shortened its development life cycle to attempt the one year deployments like their competitors.  It would appear to me that they aren't equipped to handle this.  8.1 is not ready for prime time, it fails on a very large number of devices, and even after you spend days trying to get it installed, and even resorting to customer support (like I did), it fails on other fronts (I ended up reverting).  I especially loved the part where installing SideWinder drivers caused the PC to infinitely reboot - THEIR OWN PRODUCT.

On the older PCs running 8, it just flat out wouldn't allow installation.  A service pack changing hardware requirements?  What's wrong with you Microsoft??  

Anyhow, I've been running it on my Yoga 13, and am fairly happy on that front, but I did notice a decrease in 3D performance from the HD4000.  

8.1 is a slight improvement on some of the UI and disk fronts, but overall, this is a massively botched release.  This is perhaps the worst I have seen come out of Microsoft, and I've been with their products a REALLY long time.  If they can't fix their stuff by the next release (and if the trend continues like this), I may have to go back to 7, or if they ever find a way to make Linux the dominant gaming platform, I may have to do what I swore I'd never do: move (at least for my gaming PC).

This sucks, Microsoft.  Sorry, but this unacceptable on every front.  I think Windows ME had a better launch... seriously.

Kudos to their die hard support, but as far as attempting a one year release cycle?  F-A-I-L.  Microsoft has lost their way in a way I never would have expected...  

You win Microsoft... I give up.