Q: Windows 10 crashing, but not sure why.

I should add that I have no peripherals installed on my iMac, no usb extenders, or anything. It is a brand new (less than a month old) stock iMac 21.5 4K Retina with 2TB Fusion Drive.  Windows worked fine for two weeks until this week after either the OS X update or some gremlin in the Microsoft world. I'm stumped.

Yes, this worked. There is some Intel driver that Windows Update downloads -- possibly the Iris Pro 6200 driver or one of the various Chipset updates -- that seems to hang the system.

I did two things:  First, I used "Metered Connection" to stop some of the updates, but not the Windows 10 system updates such as the cumulative or Internet Browser, etc. This allowed Windows to successfully activate. Once those updates were installed, I used Control Panel/Administrative Tools/Services to disable Windows Update.  I also used a MS Windows tool to "Hide or Show Updates" to select all of the Intel updates -- of which there are many -- to stop those from installing.

Once all of that was done, I created a Restore Point.

Interesting thing:   With the above it ran fine for hours.  Then on a whim, I turned off the "Metered Connection" setting.  Within maybe 3-4 mins, some unknown update was downloaded and crashed the system. When the Repair screen came up, Restore got me back and running.

Best I can figure, one of the many Intel drivers is causing the crash.

There are three methods:  The first is to go into your Windows wifi settings and select the option to make your wifi connection a "metered" connection. This suspends automatic downloads, unless you specifically select them.

The second option, is the Microsoft "Show Hide Updates" tool. https://support.microsoft.com/en-us/kb/3073930.  I set it up to suspend updates for all Intel drivers. Unfortunately, I have no idea how long that suspension lasts -- whether permanently until deselected, until next update is posted, or what. The documentation for it is light at best.

Last option is to go into Control Panels/Administrative Tools/Services and manually stop and disable Windows Update.  Don't do this for an initial install (or reinstall) of Windows because it needs the update function to activate Windows. But as soon as activated, you can shut it off.

Anyway, it seems the Apple issued Intel Iris Pro 6200 drivers that Bootcamp installs work fine. The newer driver offered through Windows Update seems to be the culprit. My system worked flawlessly until that new driver was issued through the Windows Update.

Just out of stupidity -- and with nothing better to do with my evening -- I again tried re-enabling Windows Update and doing an update. But before I did so, I again used the Microsoft "Show-Hide Updates Tool" to disable all Intel updates. This time it seemed to work.  As soon as updates were complete and the system rebooted, I again turned off and disabled Windows Update in the Services section, and created a Restore Point. So far, no BSOD after an hour or so of hard use. I do notice that if Updates is manually disabled and Windows can't phone home, that it will within a day or two return a "Windows is not Activated" error. For my needs, this is no problem -- all I'm doing is MS Flight Simulator, X-Box, and Steam for me and my son. Fingers crossed this is the best temp fix until the offending drivers are properly re-issued.