Double Click
esfbv100.exe and follow the installation instructions.
If you have the
.zip version you will need
WinZip & then when u open the
.zip extract it to your
Half-Life folder. I'm not 100% sure that is where you need to extract it to since I used the .exe version.
Then make a shortcut for it. The shortcut target line should look something like this:
C:\Half-Life\hl.exe -console -game ESF -noipx -nojoy -nointro -numericpings, although your directory might be different than mine.