Activation issues

[IvyisLost]

Hi, i bought the game, and installed it played it downloaded the patches, and now it asks for an activation.

It asks for a serial number but the only thing i find is something that says P/n:etc 6 numbers, i use it it says its incorrect....@.@ its the only thing i see that could be it, but then again its just numbers, so am i looking at the wrong thing, the game can expansion came as one, and there was no books just a sliding jacket the game goes into.

totally lost and confused at this point T-T