Woah woah woah woah! Calm down little buddy, bumping your thread isn't going to get you responses faster, just get you in trouble.
Now all you do is register your HL1 CD key under Steam (I believe there's a button near where you buy new packages, "register a product I already own," something like that) and it'll install HL1 to your Steam. Then just install ESF to your Steam copy of HL1, and you're good to go.