First note: On windows, npm global is global to the user (not the computer).
So, it looks like you used the account "Administrator" which means you have updated node-red for that account.
How did you open the elevated CMD?
Personally, on windows, I always adjust NPM to set the global install path to something commonly accessible (e.g. c:\ProgramData) to avoid these types of issue. Better still, run Node-RED on a linux box (or inside WSL2 on your windows box )
I recently had to put in a complaint against a desktop support engineer who was onsite and installed some software that a user asked them directly for. We have a catalogue of allowed software and no manual installs are allowed (though we do allow users to install/run software that does not require admin rights).