Installation Problem - No Half-Life Directory

Alright, for the most part, I'm a pretty intelegent individual. I went to install, and the "Install" button was greyed out. I looked at the path, and notice there was no "half-life" directory. So I went in and created it. I do have Half-Life installed. As well as Half-Life: Deathmatch and Counter-strike:source. Still the Install button was gray. So I created an ESF directory, and it's still gray. I have 4gb available of 305mb required, so it's not space. What am I missing here?

You need to run Half-Life at least once.

gotcha, thanks. Was hoping that wasn't the case, cause i'm doing it via remote desktop to my home computer while at work so i could play when i get home.