All source game crash on startup

Russosaur

Distinguished
Jul 25, 2011
166
0
18,690
When I try to play CSS, Gmod, TF2. When I launch the game it just shows a black screen with the windows loading mouse cursor and I have to end the process to close it. (Portal 2 and Portal 1 work fine) I just started happening 3 weeks ago, before I could launch the game normally in DX9 Mode but it crashes, then I launched it in DX8 mode it works but occasionally crashes. I have no idea what the problem is. My PC more than meet the requirements for any of the games. Has anyone other than me had these problems and knows how to fix them?