Windows 10 - System Events Broker high CPU use (and bonus memory leak)

[pete]

I have a room of ~30 computers.

 

On half of them, my Win 10 1607 curriculum image works without a problem (and also works on a handful of other kit it was tested on).

 

On the other half, it installs fine but sits and grinds as DCOM Server Process Launcher consumes 80>100% CPU and up to 7.5GB of RAM. Leaving it to sit there for an hour doesn't improve matters - it doesn't appear to be a one-time thing. While it might die down (and the PC becomes usable), it'll also ramp up again at some undetermined trigger.

 

Poking around in performance monitoring and selectively disabling services, the bulk of the CPU usage appears to coming from the System Events Broker.

 

BIOS versions are the same across affected / unaffected machines and the hardware is identical (Prodesk 400 G3s).

 

A similar Win 10 1607 lite image (essentially Win10, patches + Office) has worked without problems on 30 identical desktops so far.

 

There's a couple of DCOM 1610 errors in the system log which Google suggests relates to registry permission problems, but they're present on the both the problematic and unaffected desktops.

 

Any ideas? I forsee a morning of sysinternals tools and swearing at murphy.

[Homer]

I found that I was getting crash messages at logon relating to this service, on my test machine - so I nuked the service with GPO and no problems since!

[pete]

OK,

 

So, the fix(es) (which may only apply to HP ProDesk 400 G3s and their particular TPM chip implementation/drivers)......

 

Main fix:

 

Launch Task Scheduler. Go into Microsoft > Windows > Certificate Services Client and disable the task called "KeyPreGenTask".

 

CPU use should immediately fall dramatically. You may also notice Windows has tried and failed to run the "KeyPreGenTask" task ~3,000 times.

 

 

Secondary fix:

 

Launch Component Services. Go into Component Services > My Computer > DCOM Config. If you're prompted to register App IDs, do so.

 

Reboot the computer. CPU use should now be sane.

Edited September 9, 2016 by pete