Vanilla WoW 1.12.1 and Turtle WoW addon. Show the recipes/skills for a tradeskill and where to get them. - refaim/MissingTradeSkillsList
You can see right away that the "WinSxS" folder contains the most data of all the subfolders within C:\Windows. (This is normal, by the way.) You can also see the relative size of each of the other folders within Windows. If you want to drill down deeper, keep expanding subfolders....