I'm using the Windows 10 preview on a couple of machines (a laptop, and a server-2012-hosted VM). On the VM, Windows shuts itself down about every hour and has to be restarted from the Hyper-V console.
There's no indication of any error; the screen shows "shutting down", and the event log records an event from the User32 source saying that NT AUTHORITY\SYSTEM is shutting it down:
The process wlms.exe has initiated the power off of computer XXXXXX on behalf of user NT AUTHORITY\SYSTEM for the following reason: Other (Unplanned)
Reason Code: 0x0
Shutdown Type: power off
I can't say for sure, but although it's reminiscent of a "sleep" due to inactivity, my impression is it's not related to activity. I think it's happened at times when it was used a few minutes ago.
This issue doesn't happen on the laptop, which just stays on.
- EDIT adding info about the build versions in use. Both machines cited are on build 10074. If anyone reading this is perplexed that someone would use anything other than the latest build (currently 10130), remember that during a technical preview not everyone is expected to be, or wants to be, on the latest build. Users can select whether to be on the slow ring or the fast ring, which determines how quickly they will receive updates for new builds, which in turn means in theory they can defer updating until a new build has had a chance to prove its stability. Additionally it's in the nature of a pre-release product that whole areas may not yet work properly (even 30 days pre-RTM!) and issues are still being resolved. If you look on the Windows Feedback app you'll see numerous posts relating to failure to update to the current build (10130). This failure is afflicting the two machines I've posted here about, and I'll be continuing to work with whatever MS push out in response to the broken 10130 update feedback, in the hope that any findings from this exercise can ultimately contribute to the stability of the RTM version. I use a different VM with a clean install of 10130 for using 10130.
- Returning to my question, it's by no means clear that this should be an issue only with build 10074 (and indeed the other machine on 10074 is not afflicted by this issue). Nor have I seen a single post linking this issue to build 10074. In the absence of any information to the contrary, we must assume it's an issue that could affect any Windows 10 build or any version of Windows. END EDIT
I've searched and found reports of similar messages in various scenarios and Windows versions, but not a simple unexplained shutdown like this.
Why is it doing this, and how can I stop it?