look in your esf directory .. there is a file named liblist.gam
open notepad (the text editor that comes with windows)
browse to the esf directory
in the menu down where the file name is choose "all file types"
chose liblist.gam
open it
you will see at the bottom a line like this:
//gamedll "dlls\ESF-Bot.dll"
gamedll "dlls\hl.dll"
change it to this:
gamedll "dlls\ESF-Bot.dll"
//gamedll "dlls\hl.dll"
and that should do the trick