No portal in my +Games list?

Hey, so I’ve been wondering about this for a long time but I own Portal (the full game) but it doesn’t appear in my games list when I click the +. Why is this ?

[editline]29th May 2014[/editline]

This is the SECOND thread I’ve made that has been pushed back. Someone help me, like right now. >.>

TWO HOURS AGO. I NEED HELP. FOR GODS SAKE.

You are using the paid version of Garry’s Mod along with the paid Steam version of Portal? Did you click the controller icon at the bottom right on the Garry’s Mod main menu and enable portal there?

That would depend. I am using the paid version, but it is a shared game. The paid Portal…? No, I got it from the Learning with Portals promotion. But I have a friend who also got Portal via that method who had it on his game.

It could be possible but I’m not really sure how, maybe ask your friend?

Mmk. I’ll also try the controller thing, but atm my friend is on Gmod which means I can’t go on it.

EDIT: Controller was the solution! Thank you!