Garrysmod and my other games don't startup

HL2 is Installed, the Source games I have are : HL2 , TF2. And Garrys Mod. Any help? When I run Garrys mod, It is open for half a second, Then Crashes without the hl2.exe error.

Here is something else that might help :

†Åņ Nystical :lRRl:: I have problem
†Åņ Nystical :lRRl:: When I load Garrys mod
†Åņ Nystical :lRRl:: It is in the bottom, Like when you scroll internet those tabs, But for 1 second
†Åņ Nystical :lRRl:: Then goes away
†Åņ Nystical :lRRl:: Help?