VMCI.SYS Now Mandatory Driver Update From Microsoft?

Stan Kasper 1,401 Reputation points
2021-02-10T20:16:10.79+00:00

Windows 10 20H2 host. Running VMWare 16.1 On Windows guests you have the option of NOT using VMCI when installing vmware tools. However, the February Microsoft patch Tuesday update automatedly installs VMCI.SYS even though it was not there before. Can someone explain this behavior? Even when I run the guest VMWare tools install and NOT select VMCI it is still there. Is it OK to remove VMCI.SYS using the Windows device manager on the guest?

Windows 10
Windows 10
A Microsoft operating system that runs on personal computers and tablets.
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  1. S.Sengupta 20,381 Reputation points MVP
    2021-02-11T03:27:17.143+00:00

    Is it giving you error?

    If not, let it be.

    If Automatic Windows update is enabled then it will automatically download all.


  2. Carl Fan 6,856 Reputation points
    2021-02-11T07:03:15.257+00:00

    Hi,
    VMware VMCI Bus Device appears under the System Devices section of Device Manager.
    The VMCI device is used for host-to-guest communications.
    Based on the update file I checked, I find the update includes this file. So I think it comes with the update. But for VMware tool, the VMCI driver is installed by any option you select during installation. Doesn't it affect your system.
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    Hope this helps and please help to accept as Answer if the response is useful.
    Best Regards,
    Carl

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  3. Stan Kasper 1,401 Reputation points
    2021-02-11T19:42:25.123+00:00

    General question is why the change? Before it was installed with VMWare tools. Now it is a mandatory update.

    When you say 'doesnt affect your system' I am not clear what you mean. Yes, I go into devices and I see this driver and it is running. So it DOES affect my system.

    I didnt have this before. And I have been running this for over 10 years. Now it is mandatory. Why?

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