I think it is a relatively recent (Win8?) addition, and explorer has been the shell since '95. I take adding a specific button for it as an admission that Explo

I think it is a relatively recent (Win8?) addition, and explorer has been the shell since '95. I take adding a specific button for it as an admission that Explorer is getting increasingly buggy, so users are needing to restart it more. Before then you could do the same thing from the same task manager just in two steps: kill the existing explorer.exe and start a new one from the Run command in the menus.