You don't need by Half-Life to use EPB.
Just use the installer and point c:\program files\steam\steamapps\email account\counter-strike\
then all must be ok. If not check if the EPODbot folder is located in to the your
c:\program files\steam\steamapps\email account\counter-strike\cstrike dir, if yes then check out liblist.gam located to the same dir.
Find the line
gamedll "dlls\mp.dll"
and replace it with
gamedll "EPODbot\EPB.dll"
then start the server and type epb_addbot. Sinse version 5.1 all the commands of E[POD]bot will start with the epb_ prefix.
To activate the bot menu just use the "p" key or type in to the console
epb_botmenu
and the menu will show up.