Hey,
I have been trying to install forge 1.7.2 all day and seem to be encountering the same problem, I have watched several tutorials and followed them exactly as they do it, but still don't manage to get it working.
The problem I have is that once I am on the minecraft launcher, I choose the forge file, make sure it is the correct version, click Play, after that nothing happens, it doesn't load minecraft at all...
I have tried several versions of forge, even one that my friend uses which I know is working. Any help would be greatly appreciated!
EDIT: 1.6.4 Forge works, just not 1.7.2