You don't need to log in to download the game or any updates. If you've not deactivated it and not changed your PC or reinstalled windows since the last time you played, you won't need any information. Just download the files and use them.
I understand this would only be a temporary resolution, but it could get you up and flying.
The world is going mad. Me? I'm doing fine!
Asus Sabertooth X58, i7 950 @4GHz, 6GB corsair Dominator 1600 MHz, EVGA GTX 570, Samsung 1Tb, 60 Gb OCZ Vertex 2E SSD