Problem with friend's trial account

Yesterday my friend downloaded the free trial client and created a free trial account while at my house. When he went home today and installed the client on his computer, and endeavored to log in via his trial account, he was met with this: http://i.imgur.com/rGyz03B.png

Is anyone aware of what could be causing this issue and how he could go about subverting it to actually play the game? Thanks in advance.

It seems that he donwloaded a full game client instead of the trial one.

He claims to have downloaded it from the trial page. He also played his trial account on the full client while at my house. I don't think that's the problem.