UPDATE (2018-05-16): Microsoft just released a new build of RS5 (17672) that they say resolves this issue. You can find the blog post here. To test, be sure to remove the EnableActivityFeed value of 0 below that you may have created to work around this issue.

If you’re reading this, you may be having an issue with Explorer.exe getting stuck in a crash loop on Windows 10 RS4 (17133/17134) or RS5 (17604+). After some messing around, it looks like the root cause may be related to the new Timeline feature that appeared in RS4. Here’s what I found on my two machines that experienced this issue:

Open Event Viewer (eventvwr.msc) and go to the Application log under Windows Logs

log under Look for Application Error events where Explorer.exe is the application that crashed

If these events have a faulting module of StructuredQuery.dll, then this is probably the same problem I ran into

Here’s what I did to resolve the problem (at least temporarily):

Open Task Manager NOTE: Keep it open because you’re going to lose your Start Menu/Taskbar which aren’t working anyway.

Kill Explorer.exe to stop the crash loop

Open the Registry Editor

Go to HKLM\SOFTWARE\Policies\Microsoft\Windows\System

Create a new DWORD value named EnableActivityFeed with a value of 0 NOTE: This DISABLES Timeline’s activity feed feature.

with a value of Restart your computer

Login

At this point, your Start Menu/Taskbar should work fine. Timeline’s activity feed is disabled, but at least you can use the rest of the shell without an issue. Going through some of the posts on the Feedback Hub, others seem to have had success by rebuilding their file indexes. I haven’t tried this, so YMMV. However, if you’re wiling to try it, there’s a great tutorial on How-To Geek that can walk you through this.

At this point, I would highly recommend upvoting this issue on the Feedback Hub. There are multiple posts related to this, so pick the one(s) most relevant to your system(s):

Hope this helps!