Can't get forge to install

[blazindragon]

I'm installing Minecraft on to a new cpu and I can't get forge to install. When I try to use the forge 1.6.4,it tells me to manually run that version of minecraft, but I can't do that since you can only download 1.7.5. So I try forge 1.7.2 and I get the same message, expect, with 1.7.2. Am I missing something here? Is there any way I can get forge to work? Thanks for the help.

[blazindragon]

I think I have ran vanilla.  I downloaded forge, tried to install, got the message.  Opened minecraft with nothing except the game, loaded a new world, quit game.  Tried to install and still got the same message.

[blazindragon]

Okay, how do I download older versions of minecraft?  Such as 1.6.4 or 1.7.2.

[blazindragon]

Okay, I don't play it, my kids do, so I just double click the icon, then hit play game.  I've never looked at the launcher or anything like that.  But I will try this as soon as I get home.  Thanks for the advice.