Edwin I believe I read about this one too on the same site that had the old start menu tweak & new calender tweak but did not see any warnings there. Thanks for testing and warning others as I tried the calendar tweak with no ill effects just after I read your post in that thread.
Thought you were having nasty fun with Cortana
I tend to only try tips listed here or in the tutorials. Those 3rd party ones can be terrible.
I know that I'm not going to try that "hack" out.
I'm going to try it now!
If I get 'locked' out, I'll see ya after a clean install!