> For Notepad a frustrated engineer had produced a change-set to fix all of them

Hey, that was me (JeffMill). I was a dev lead for the Windows shell team at the time, and I got frustrated with notepad not getting any attention, so I spent a weekend and made the changes you describe and more, and had one of my reports code review it. I checked the changes in, and that week, some of the members of test team (remember those?) had a cow and my lead pulled out all of the changes.

I'm still at MSFT, now as an architect, so it turned out not to be a career limiting move, but I certainly should have discussed my plans more broadly rather than just "cowboying" those changes in.