Because steam comes from there. You run half-life from steam. You don't need to use the old version. From what you ahve said, it is 100% ovious you are running the old version of half-life.
Get steam from the steam website and install steam. Then run half-life once and install esf to the steam HL directory. Once there, you go to play games (under the steam menu; right click on the steam icon in your lower right corner to see it) and you will scroll down to see the ESF game.
thanks for the help. i waited until my dad was drunlk and then i asked him if i could use his credit card. i bought hL with some other mods as well (like DoD, Ricochet, team fortress etc..) My esf works noe thank for the help!!