Installation Process Hl2/Hl1/Steam

When I go about installing these for esf do I 1st install steam, then install hl1? or do I install hl1 then steam? Then once that is complete do I install esf or activate steam with my hl 2 account. Also does hl1 come for free if I buy hl2 or do I need to buy both of them seperatly?

Sorry for all the noob questions :shocked:

ever used the search fuction , esf is not for hl2 , you register the copy of hl then steam will get you to download the new hl installer or you can go find the steam full install file off hl2files , then install esf 1.2 & the patches (or 1.2.3 full if u have the 1.2.3 full installer)