serial registration window

[irishfan]

well i just bought amnesia the dark descent. I logged on to shelf and it gave me the game serial number and 3 links that said download to windows, mac, and linux. i have windows so i clicked the download windows link and it didnt work. so i scrolled over the serial number and it said to copy and paste into the serial registration window. i figured that what you have to do then to play the game but i couldnt find the serial registration window.