Quote Originally Posted by Grif View Post
Steam sometimes acts up and doesn't recognise your PC, even though you already logged in and are actually using the Steam browser to... yeah, you get the picture. Something to do with different IPs or different configurations, I reckon, since I had that problem on and off some time back.
Happens a lot if you log into Steam with different computers too. I get that message pretty often since I'm often logging in on my desktop and laptop.