Portal 2 no steam?

[Torbjorn/ŜĊĤǺDŽŊƑȒȄǛDȄ]

Hello. I have Portal 2 on Steam and I tried to play some recently. When I openeed it up, I found something other than the main menu. I found a button saying "no steam" and a button saying "quit." I can't click the "no steam" so I have to click "quit." And then, my game closes. Can someone please help me?

[ KARR™]

Tried this post in the Portal 2 forums...?

http://steamcommunity.com/app/620/discussions/0/864951657921425392/