Solved Well, I'm in!

After a few failures to upgrade to 8.1 with these errors

0xC1900101 - 0x40017
0xC1900101 - 0x30018
0xC1900101 - 0x20017

With a retina MacBook Pro 10,1

When EFI booting Windows on my machine it is necessary to remove the Intel video driver (long story) so only the Nvidia GT650M is usable.

As my problems upgrading to 8.1 seemed to be graphics driver related I tried to update to the later drivers from Nvidia but during removal of the driver already in use the screen just went black and the system just got stuck there - whatever I did I couldn't proceed. Neither would the system reboot to a desktop - just a flashing black/grey screen. I'm sure I tried every method possible but still no good.

Anyway I fixed it up a couple of times and decided to try it in safe mode. Also no good .
As soon as the driver was removed the system stopped recognising that the Nvidia card was present and therefore the Nvidia installer could not proceed with installation

So I decided to re-install Windows 8 in a shiny new Bootcamp partition.

Once installed I ran all the updates and tried again to update to new Nvidia drivers.
Same story as before

I eventually got the old driver out and the new 327 driver installed in safe mode :thumb: and it rebooted successfully to a desktop

Once that was ok I disabled the Windows Firewall and Defender's real-time protection then downloaded the upgrade and ran it. It ran ok and after 8 reboots (I think it was) it booted successfully

So, it's installed and running quite nicely
It seems quite good actually

Congratulations on your success!

Lol, thanks. I don't give up!

I can see that you are quite a digger!

Doesn't give me a warm fuzzy though being a dual graphics laptop person myself. Maybe just a Mac thing, I hope.

popeye said:

Doesn't give me a warm fuzzy though being a dual graphics laptop person myself. Maybe just a Mac thing, I hope.

Click to expand...

My suspicion is it's more to do with Nvidia drivers than dual gpu's - but I've been wrong before

Just a word of warning though. Enable Safe Mode in your boot options first (if you haven't already) as you may be glad of it.
http://www.eightforums.com/tutorials/2758-safe-mode-add-windows-boot-manager-windows-8-a.html

Duckface said:

popeye said:

Doesn't give me a warm fuzzy though being a dual graphics laptop person myself. Maybe just a Mac thing, I hope.

Click to expand...

My suspicion is it's more to do with Nvidia drivers than dual gpu's - but I've been wrong before

Just a word of warning though. Enable Safe Mode in your boot options first (if you haven't already) as you may be glad of it.
http://www.eightforums.com/tutorials/2758-safe-mode-add-windows-boot-manager-windows-8-a.html

Click to expand...

Thanks a bunch, every little tidbit helps. I'm trying to glean as much info as possible before making the leap myself. This is great advice as I don't have it enabled right now.