Half Life 2/Steam Problem

[Morbus19]

I have a disc copy of Half Life 2 (the old 5 CD collection...). I installed Half Life 2, but whenever I click on the Half Life 2 icon on the desktop it takes me to Steam, where it offers me deals on a game I just bought!

I can't figure it out. I can't find a half life 2 exe in the Valve ---> Steam program files. I can't activate half life 2 on Steam because all I received were the 5 discs and therefore did not get the activation key (Do I even need to activate it?).

I can't find anything on it at Steam Support.

Can someone please help me out? I've been trying to figure this out for hours and have made little progress.

 

[PimpinPenguin]

You are required to activate your copy with Steam. Steam activation is required regardless if it's the CD version or the DVD version. I would return it and get your money back if it has no activation key. Steam is having a sale where all Half-Life games are 66% off. you may want to consider buying it off Steam.