Need Help

I’m having problems playing Black Mesa.Downloaded the game a few days ago and its been working fine until today,every time I try to play the game it will work for about a minute then switch back to my Desktop its doing this constantly any help would be great,thanks.

Does it make it to the menu?
Try verifying your game cache (The Source SDK Base 2007), and if that fails, backup your saves folder and reinstall Black Mesa.

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.