Gmod Dedicated Server Problem

I’m trying to install a Gmod dedicated server, I’ve been using these instructions;

And have set up everything according to them. I’ve installed the Gmod, Cs:s, and Hl2:dm files, using hldsupdatetool. The problem being, when I start up the server using the GUI, it shows CSS and Hl2:Dm as the only available games, which I’m able to start a server for, but doesn’t show Gmod. I moved the Garry’s Mod folder out of the “\orangebox” directory and into the main folder were the dedicated server exe is located, which made Gmod pop up in the available games, but didn’t allow me to create a server (Got to the loading bar then hung). So yeah, what would I have to do?

If it matters, here are my comp specs;
AMD Quad @ 3.1ghz
ATI 5770
2g Ram