Blood stains and purple eyes glitch!

I recently downloaded Black Mesa(Noob on this site) and every single NPC has blood stains all over them with purple eyes. This is definitely a glitch, how do I fix this??

Did you install to the correct directory?

That glitch should only happen if you are running it in dxlevel 7 or you didn’t install it correctly.

I installed it to the default directory:
C:\Program Files (x86)\Steam\SteamApps\sourcemods\BMS

Also sometimes the acid instead of green looks checkered purple and theres a lot of graphical issues

BTW I’m running this on Windows 7 Ultimate 64bit

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.