I'm trying to download some mods but I need minecraft forge ad it comes up with that message. So how do I run 1.7.2, I have no idea how to change it. I'm new to minecraft pc
  Thanks:)
  Also can I change it back to 1.8 after and still use the mods? It won't mess up my worlds will it? 
  Read more: Minecraft forge download error message. You must manually run 1.7.2 first?  
