Body Shop is a Maxis-made program - it comes with your game and is already installed if you have the game installed. There should now be no folder called Downloads in your The Sims 2 folder.
CUT (or CTRL-X) your Downloads folder and PASTE (or CTRL-V) your Downloads folder to your computer's Desktop. In fact, this trick often works when you cannot get your custom objects showing up with a new expansion install.
This trick has absolutely nothing to do with whether the content not showing up is sim/Body Shop related. It is especially useful if you have just installed a new Expansion Pack or Stuff Pack and content that was working before you installed now won't show up. This handy little trick often helps when the game isn't recognizing custom content that should be working.
