Okay here is what i know. (I´m through this 2 times now) If u have any original game (means box and CD-Key somewhere written on) just go for Steam-Support and regisiter there. It doesnt need ur account to have one there.
When ur finished registering then make a new question. There are pull-down menues... take what fits to ur case.
AND!!! make a photo of ur CD-Key (which is mostly written on a gamemanual) and sned it as attachment. 2 days of waiting and fine. An email follows which gives u a new PW. (change it after u used it to login)