Sorry in advance - this is more of an answer to potential questions that may arise from the latest large windows 10 update

 

So having just updated 2 of my vms to the latest windows 10 - and a 2 hours wait i found my vms had an issue so here is what i had to do for my updates to work

 

Running the updates directly with a normal windows reboot fails on a blue screen - so instead get to the "Restart Now" option and do an "Update and Shutdown" from the normal windows shutdown instead

Go to unraid and edit the VM to allow it to only use core 0 and start the vm back up - the update will then work flawlessly and run through to desktop

 

After updating i then shut down my vms and allocated my cores back. After booting i found that windows only saw 1 core even though more were set and were correct in the xml file and the log files

I then tried removing some cores and rebooting - this had no affect

I then did a forced vm shutdown while windows was running from unraid directly as at this point i was willing to try anything - this resolved my issue

 

On reboot windows was forced to re-check the cpu count and picked up all 8 i allocated, i did the exact same on my other vm and 4 showed us as expected. I have no idea why this worked but it did for me and isn't something i would have normally tried

Please note that doing this may cause windows to try to do boot recover and may even cause boot issues so do this at your own risk! it worked for me but may not for others

 

Regards,

Jamie

Thanks for documenting your experience with this.  It may very well help others avoid problems with the new "anniversary update" v1607

 

One other thought:  I've found that the major updates are FAR more reliable if you do them by running the Setup utility from a bootable media you create using Microsoft's Media Creation Tool instead of doing it through Windows update (which I presume you did).    I've seen several systems that would fail to successfully do the update via Windows update; but update just fine when done using bootable media (either a DVD or a USB flash drive).

 

Not sure if it'd still have the same CPU assignment issue that way, but might be worth a try.

 

I made a ISO of the update, mounted it as a drive and ran the setup with the VM running normally.

It worked well, although I did see one error message during the update that I didn't capture.

My VM has 2 threads of 1 real core allocated, and its 32bit Windows 10 Home.