I think steam did it via their own method instead of what we are used to seeing. I remember wondering about this, but I do remember seing the litle steam grey box pop up “updating” once when starting. I remember because it concerned me as I wondered “uh oh, what’s wrong with my files and what is steam doing”. But I have it. And, I must say, with the steam edition I have not had a single problem from initial load to patching. I’ve never had to reinstall. I think the only problem I had was the intiial problem everyone had where the blue bar hung once on initial load.