"SETUP HAS NOT DETECTED A VALID STEAM INSTALL"
Hi all. When installing this mod in my Half-Life directory It gives me "SETUP HAS NOT DETECTED A VALID STEAM INSTALL". I purchased Half Life Source for 9.99 off the Steam website and it's in my Steam directory. What else am I doing wrong? I tried activating HL:S in the steam menu but they didn't send me any CD key when I purchased this game. All I got is a customer number for proof of purchase.