Lost second processor after Windows upgrade

[fog]

Thanks a lot for such a great monitor.

Using HWiNFO I have never had any issue until today when updated my Windows 8.1 Pro x64.
Installed only 2 updates:
1) Update for Microsoft Windows KB3042085
2) Update for Microsoft Windows KB2976978

And the second processor including all sensors (except of the second Fan Speed) of my system has been disappeared in HWiNFO after these updates.
At the same time, all logical cores from the second "lost" processor added to the first one.

Open Hardware Monitor still shows correctly 2 physical processors.

Please check the image attached below:

 

[Martin]

Please attach the HWiNFO Debug File as described here: http://www.hwinfo.com/forum/Thread-IMPORTANT-Read-this-before-submitting-a-report
then I can check it in more detail.

 

[fog]

Martin,
Thank you for your prompt response.
Please check the attachments.

 

[Martin]

I'm not sure what exactly happened there, but it seems something is preventing the CPU to provide certain details. Maybe the update did ?
Can you please try to run HWiNFO32 there if that will report correct CPU information ?
Also I'm not sure if you would be willing to uninstall those updates to see if that was the cause.

 

[Martin]

Update - apparently there's some issue with Hyper-V under Win8.1.
Have you maybe enabled Hyper-V ?

 

[fog]

Never enabled Hyper-V.
Tried to run HWiNFO32 instead of HWiNFO64 - the same result (no second CPU).
Uninstalled KB3042085 and KB2976978, disabled all antiviruses/HIPS, restarted system, - nothing changed.
Rollbacked the whole system (have an old back-up image) - the issue disappeared (HWiNFO64 found the second CPU with all sensors).
It seams, with KB3042085 and KB2976978 installed, Windows changes something in registry or/and file system preventing HWiNFO to find the second CPU, and standard update uninstallation does not help.
Will be waiting for the next Windows hotfix or updated HWiNFO.
Regardless, thank you for your work, Martin.

 

[Martin]

You're welcome. I don't think that only HWiNFO was affected, other tools might have been as well. But now that it works, it's not possible to prove it.