I am soo happy this project is finally done, and I will do what it takes to play it 
So far my initial download of the blackmesa.zip containing the 3 files is reported as corrupt by the standard XP pro .zip program. I am forced to download a 3rd party program, 7-Zip to get the folder blackmesa with blackmesa-setup.exe, blackmesa.7z and the .md5 file inside. I run the setup file and it is taking a very long time to extract but if it is not corrupt I will be ecstatic. Crosses fingers.
Edit: Ok, next day I was able to install it and play for a bit. I quit and stopped and started Steam and the game is not in my list. I tried the desktop shortcut, “C:\Program Files\Steam\Steam.exe” -applaunch 218 -game “\Program Files (x86)\Steam\steamapps\sourcemods\BMS” and it gives error that gameinfo.txt is not in the bms folder when I see it there. It is installed in the default folder as instructed and I still can not play it 
Edit: Finally figured it out, at least the desktop shortcut works sans the (x86) and the game starts… not in my steam list yet but as I said, I’m not complaining lol
Founded in 2004, Leakfree.org became one of the first online communities dedicated to Valve’s Source engine development. It is more famously known for the formation of Black Mesa: Source under the 'Leakfree Modification Team' handle in September 2004.