Hello,
as far as I know, the latest Windows update does not change the way the COM+ and ActiveX objects work. This shall not be related. The issue you are facing is strange indeed.
Let's pick up one plug-in (CAN communication) and see its registration details.
Run the "command prompt" as administrator again, then cd to "c:\NXP\FreeMASTER 3.2\FreeMASTER" and use the regsvr32 command without the /s (silent) option:
regsvr32 plugins/can/focpgi.dll
The confirmation shall appear:

Then in the same Command Prompt console, start the Registry Editor by command:
regedit
It will take some time (can be few minutes) then the editor will appear. Navigate to
Computer\HKEY_CLASSES_ROOT\WOW6432Node\CLSID\{C10A92C3-7D47-4FDC-94B6-64B8E5C85E01}
This entry represents the FreeMASTER-over-CAN plugin (focpgi.dll). It shall be present in the registry.

You can check the InprocServer32 entry points to the correct focpgi.dll file.

The "Implemented Categories" ID is the one FreeMASTER uses to locate all plug ins using Windows COM Category API. Just to be sure the plug-in category exist, please check the Computer\HKEY_CLASSES_ROOT\Component Categories\{48A185C0-FFDB-11D3-80E3-00C04F176153} key in the Registry editor, you shall see the "MCB Communication Plugins" text value:

Another experiment would be to remove the /s switch from register.bat script and run it. You shall see a registration confirmation box for each DLL.
Please share the respective screenshots or errors. Thank you for your cooperation.
Regards,
Michal