Got HL1 But wont install

[DxM]

I have HL1 But when i get to the DIR the Install button will not become avaliable WTF am i doing wrong.. :Sigh:

Help PLEASE

DxM(DeathByMetal)

 

[Skyrider]

Make sure you install Half-life 1 and launch Half-Life atleast ONCE before you are going to install Earth Special Forces. And once you done that, re-restart steam so ESF will be added in the steam list.