Patch KB 3124200, released yesterday, probably installed itself on your Windows 10 system overnight. That's why you faced a reboot this morning. (I say "probably" because it only installed on Windows 10 version 1511/Fall Update PCs that aren't on a metered connection.) If you have the patch, the internal version number (to find it, type "winver" in the Cortana search box) will read Version 1511 (OS Build 10586.36).
We've had almost no documentation about any Windows 10 version 1511/ Fall Update patches since build 10586 appeared on Nov. 12. This new patch is no exception, but I'm seeing reports it may have fixed one bug that caused the WLAN AutoConfig service to crash randomly, bringing down Wi-Fi service in the process. According to poster pestilence2k on the Microsoft Answers forum, the bug was introduced by cumulative update 5, KB 3116908, on Dec. 3.
If you can confirm that Windows 10 is now suddenly, miraculously, keeping your Wi-Fi connected, please drop a line in the comments.
As is common in the Answers forum now, well-meaning Microsoft employees chime in with suggestions that are totally off the mark. In this particular case, the problem was a bug in patch KB 3116908, and no amount of voodoo and entrails reading could dispel the bug. Microsoft had to fix it.
Of course, by not describing the changes, Microsoft avoids having to say nasty things like, "This patch fixes a Wi-Fi bug introduced in the previous patch." There's a method to the madness.
In the five weeks since build 1511 appeared, I count six cumulative updates:
- Version 1511 (OS Build 10586), released Nov. 12, is the first version 1511 -- the one that raised the old RTM build 10240 version of Win10 to the November Update/Threshold 2 level
- Cumulative Update 1, KB 3105211, Nov. 10, build 10586.3
- Cumulative Update 2, KB 3118754, Nov. 18, build 10586.11
- Cumulative Update 3, KB 3120677, Nov. 24, build 10586.14
- Cumulative Update 4, KB 3116908, Dec. 2, build 10586.17
- Cumulative Update 5, KB 3116900, Dec. 8, build 10586.29
- Cumulative Update 6, KB 3124200, Dec. 17, build 10586.36
We also saw a compatibility update for upgraders released yesterday, KB 3124260. No details about that one, either.
At this rate, I wonder how many cumulative updates we'll see before the first Redstone release hits the mainstream, sometime near the middle of next year.