How to identify the blocked Google extension and remove it from the OS?
Here is an easy way to identify which kernel extension is causing this MacOS blocking of its install.
When you are on the Security &amp; Privacy System Preferences… telling you:
System software from developer &quot;Google, Inc.&quot; was blocked
from loading.

just select Allow once just to be able to get its real name and not to keep it installed.
Then let the complete boot of MacOS terminate, and open a Terminal or xterm.
Enter the following command to extract from all your kernel extensions the one which developer might be Google with:
/usr/bin/sudo kextstat | egrep -i '(^Index|google)'

The 6th field of output of this command is the bundle name under which this extension is registered in the MacOS kernel.
Let's say for this example its name is:
com.google.kext.foo

Next go to:
cd /Library/Extensions

and search for this bundle name within all the Google looking directories:
grep 'com.google.kext.foo' [gG]oogle*/Contents/Info.plist

Then if Google made its job of developer correctly you should be able to find on the web what this extension id doing.
And you will know if you need it or not.
If you want to keep it within your /Library/Extensions but not loaded within MacOS, just reboot.
Investigation closed.