Yes, this looks like something gone wrong in uninstall. It is really important that you follow the guidelines that you got from development to the letter. This Windows dll-thingy has nick names that cannot be said here.
I want to add one possibility, a far-fetched one, but it seems that you MIGHT have done some manual tasks in order to correct the situation. If you have MOVED a .dll to a new place, you might not understand that the software/Windows follows the move - in some cases - and thus you might still be using it, or rather software is using it in your new place. So, you have to make the .dll unusable, like renaming the filename and the extension to make sure - or just rather delete it.
Original Message:
Sent: Nov 05, 2025 01:12 AM
From: James Lin
Subject: VMware Workstation 25H2 not wil start
Tim,
- After installing VMware Workstation 25H2 on your host, are you absolutely certain that you powered off your host and powered it back on? This step is critical, please do not ignore it, and please explicitly confirm whether you rebooted your host. It is not clear from "yes I did that started the host still does the same thing" whether you rebooted after installing Workstation 25H2.
- After you've rebooted your host, can you confirm that the file properties of
%WINDIR%\System32\Drivers\vmx86.sys still reports "25.0.0.0" as the file version? We need to make sure that there isn't something else on your host that is rolling back the driver version. - If it does still report "25.0.0.0" after you've rebooted your host, are you still encountering the "Version mismatch..." error when attempting to power on a VM?
Please take some time to provide clear and detailed answers to all of my questions. Thanks!
Original Message:
Sent: Nov 04, 2025 11:28 PM
From: Tim Mees
Subject: VMware Workstation 25H2 not wil start
Okay, I want to say that the file vmx86 version 25.0.0.0 is in system32/drivers so it is present.
Original Message:
Sent: Nov 04, 2025 04:32 AM
From: Tim Mees
Subject: VMware Workstation 25H2 not wil start
this file is in that directory
Original Message:
Sent: Nov 04, 2025 04:14 AM
From: James Lin
Subject: VMware Workstation 25H2 not wil start
That's weird. Can you:
- Uninstall VMware Workstation. Reboot your host if the uninstaller asks you to.
- Verify that
%WINDIR%\System32\Drivers\vmx86.sys no longer exists. If it does, then run Command Prompt as Administrator, and enter net stop vmx86 to stop the driver, and then you can delete (or rename) that file. - Reinstall VMware Workstation.
- Verify that
%WINDIR%\System32\Drivers\vmx86.sys exists, and if you right-click on it, choose Properties > Details, "File Version" reports 25.0.0.0.
Original Message:
Sent: Nov 04, 2025 03:47 AM
From: Tim Mees
Subject: VMware Workstation 25H2 not wil start
yes I did that started the host still does the same thing
Original Message:
Sent: Nov 04, 2025 12:59 AM
From: James Lin
Subject: VMware Workstation 25H2 not wil start
Tim, that doesn't answer my question. I know that you installed the new version, but have you rebooted your host afterward?
Original Message:
Sent: Nov 04, 2025 12:20 AM
From: Tim Mees
Subject: VMware Workstation 25H2 not wil start
No, the new version is installed, I always get this message