Hi,
I downloaded the recommended Windows installer build for Forge 1.7.2. The first thing I notice is that when I run it, it tells me something about grabbing 0 libraries. (I went and manually downloaded the libraries and reinstalled after this)
Windows tells me the program didn't install correctly. I clicked 'install with recommended settings', hoping that would solve something.
I then open Minecraft and select the Forge profile it created for me. I click 'Play', a few seconds later the launcher pops right back up.
The dev console gives me this:
Latest FML log:
I've tried this with the latest build and the jar installer with the same result.