Idling Vista and newer Windows VMs freeze my host 64-bit W7 PCs once in a while?

[ant]

Hello.

It seems like my idling Windows (newer versions like Vista, 7, and 8.x; doesn't matter if it is 32-bit or 64-bit; using 1 GB of RAM) VMs like to freeze my 64-bit W7 (HPE and EE) SP1 host PCs to almost lock up for a few minutes. The way it starts is that my host gets slower and then freezes (no responses from my USB mouse cursor, USB keyboard, etc.) since I am using the host's softwares. And then, I will have to wait for the host to unfreeze most of the times.

I have seen this problem with previous VMware Workstation versions (latest to older versions (v7 IIRC) from several years ago) on two/2 different Intel Core i5 systems (Lenovo ThinkCentre M81 (1730-A45) and Dell Studio XPS 8000) with ATI/AMD video cards machines with 8 GB of RAM and SATA HDDs. I watched for symptoms on my host. I saw no heavy HDD activities (no lights shown). I tried disabling some hardwares (e.g., optical drives) in guest VMs, running SMART tests, disk checks, etc. No problems. I also don't see this problem with older Windows versions like XP. I also don't run more than one VMs at the same time since one VM is already slow enough.

Do I have a hardware conflict between the guest VMs and hosts? I checked Windows guests' power management and screen saver, but they were disabled. I even tried upgrading old VM versions to use the latest v10. They did not help. Are there anything else to look for and try? Does anyone what's up or even have this annoying problem?

Thank you in advance.

[ant]

I also noticed audio can stop during the freeze after a few seconds. Everything resumes after a minute though.

[ant]

OK, I think I finally narrowed it down that caused it: Windows guests' WinSAT.exe process, from Task Scheduler, since disabling it forever did not happen again so far. Running it manually instead of idling reproduced it! My notes:

SYMPTOMS:

-~1 minute slowdowns and freezes start after new guest Windows (Vista to 8)'s 15 minutes of idling for WinSAT.exe (Windows System Assessment Tool) to hog CPU and screen to go black (already disabled sleeps, screen saver, etc.). What else to check for these 15 minutes idled times beside power management?

-guest Windows display goes black (sleep?) with guest's brief disk activities, but I disabled sleeps, screen saver, etc.

-host's audio plays a little longer and then stops until PC resumes.

-no heavy HDD activities in hosts during the freeze.

-happened since VMware Workstation v8.

-reproduced in 3 different hosts (64-bit W7 (SP0 & SP1) and 64-bit W8.1).

TRIED:

-watched guest's taskmgr at 15 minutes. winsat.exe was hogging CPU during the display blank out. Manually running winsat.exe reproduced it too.

-disabled winsat.exe in task scheduler's Microsoft\Windows\Maintenance (did not see any settings for 15 minutes though -- there is one for 10 minutes).

-removed guests' hardwares: usb controller, sound, and optical disc drive

-tried w7 basic display in guest

-tried high performance power plan, with custom settings, in guest's Windows

-disabled sleeps for display, computer, and disk in guests' Windows

-disabled PCIe's link state power management in guests' Windows

-disabled USB settings' USB selective suspend setting in guest's Windows

-ran gmsartctl tests on host

-no security suites in both guests and hosts

Now, WHY is this causing my host PCs to freeze if guest's WinSAT.exe runs from Task Scheduler? Is that normal? Is anyone else having this problem too?

[ant]

Can someone please kindly try running Vista/W7/W8's WinSAT manually task scheduler (maintenance) and see if it temporarily hogs and freezes the host machine too?